Archive for July 5th, 2005
Conclusion
Achieving and maintaining healthy lifestyle behaviors including activity and food intake can help weight management by helping to prevent weight gain. Prevention of weight gain and achieving modest amounts of weight loss can improve overall health.
In today’s society, the environment is conducive to less activity than previous decades, more food availability in larger quantities, and higher caloric density. Therefore, concentrating on factors to limit the environmental influences is critical. It is important to acknowledge those factors we can change and those we cannot. It is also important that dietitians and other health care providers be in the forefront of lobbying for public health policy, third party reimbursement for treatment and management, and adequate community resources to address weight status and weight-related illness. We need to document our outcomes, develop flexible and individualized goals for patients, and continue to support research efforts to improve the efficacy of treatment. Such documentation requires thorough assessments and follow-up: medically, nutritionally, be-haviorally, and psychologically. Based on current available treatment approaches, goals need to stay focused on a “healthy lifestyle” targeting the environmental factors that allow for gene expression, particularly physical activity and food choices directed toward less calorically dense foods.
We must educate ourselves and the medical community as to the physical and psychological impact of our recommendations. We must include our patients in the decision making process and inform them of the known positive outcomes they can achieve.
ADA Position adopted by the House of Delegates October 20, 1996, and reaffirmed on September 12,1999. This position is in effect until December 31, 2005. The American Dietetic Association authorizes republication of the position paper, in its entirety, provided full and proper credit is given. Requests to use portions of the position must be directed to ADA Headquarters at 800/877-1600, ext 4835 or ppapers@eatright.org.
Recognition is given to the following for their contributions:
Authors:
Sue Cummings, MS, RD (Massachusetts General Hospital Weight Center, Boston, MA); EUen S. Parham, PhD, RD (Northern Illinois University, DeKalb, IL); Gladys W. Strain, PhD, RD (Mt. Sinai School of Medicine, New York, NY)
Reviewers:
Gaston P. Bathalon, PhD, RD, FADA (US Army, Natick, MA); Ann M. Coulston, MS, RD, FADA (nutrition consultant, Woodside, CA); Sharron Dalton, PhD, RD (New York University, New York, NY); Dayle Hayes, MS, RD (nutrition consultant, Billings, MT); Joanne P. Ikeda, MA, RD (University of California, Berkeley, CA); Melinda Manore, PhD, RD (Oregon State University, Corvallis, OR)
Members of the Association Positions Committee Workgroup: Barbara Baron, MS, RD (Chair); Mary Marian, MS, RD; Lillie Williams, PhD, RD, FADA; James 0. Hill, PhD (content advisor)
References
1. US Department of Health, Human Services, Center for Disease Control and Prevention; National Center for Health Statistics, Maryland. Prevalence of Overweight and Obesity Among Adults: United States, 1999.
2. Wolf AM, Colditz GA. Current estimates of the economic cost of obesity in the United States. Obes Res 1998;6:97-106.
3. Allison DB, Fontaine KR, Manson JE, Stevens J, Vanltallie TB. Annual deaths attributable to obesity in the United States. JAMA 1999;282:1530-1538.
4. Dheeksha M. National Institute of Health, National Heart, Lung, and Blood Institute Clinical guidelines on the identification evaluation, and treatment of overweight and obesity in adults—the evidence report. Obes Res 1998;6:121S-122.
5. Anderson JW, Kontz EC, Frederich RC, Wood CL. Long-term weight-loss maintenance: a meta-analysis of US Studies. Am J Clin Nutr 2001;74:579-584.
6. Schick SM, Wing RR, Klem ML, McGuire Tetal. Persons successful at long-term weight loss and maintenance continue to consume a low energy, low fat diet. JADA 1998;98:408-413.
7. Wing RR, Hill JO. Successful weight loss maintenance. Ann Rev Nutr 2001;21:323-341.
8. Kassirer JP, Angell M. Losing weight—An ill-fated New Year’s Resolution. N Engl J Med 1998;338:52-54.
9. National Institutes of Health and National Heart, Lung and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults—The Evidence Report. Obes Res. 1998:xi.
10. Leibel R, Rosenbaum M, Hirsch J. Changes in Energy Expenditure Resulting from Altered Body Weight. N Engl J Med 1995;332:621-628.
11. Schwartz MW, Woods SC, Porte D, Seeley RJ, Baskin DG. Central nervous system control of food intake. Nature 2000;404:661-671.
12. Bray GA, York DA. Clinical review 90: Leptin and clinical medicine: a new piece in the puzzle of obesity. J Clin Endocrinol Metab 1997;82:2771-2776.
13. Erlanson-Albertsson C, York D. Enterostatin—a peptide regulating fat intake. Obes Res 1997;5:360-372.
14. Barsh G, Farooqi I, O’Rahilly S. Genetics of body weight regulation. Nature 2000;404:644-651.
15. Perusse L, Chagnon YC, Weisnagel SJ, Rankinen T, Snyder E, Sands J, Bouchard C. The human obesity gene map: The 2000 Update. Obes Res 2001;9. 8135–169.
16. Maes HH, Neale MC, Eaves IJ. Genetics and environmental factors in relative body weight and human adiposity. Behav Genet 1997;27. 325–35.
17. Stunkard AJ, Sorensen TIA, Hanis C, Teasdale TW, Chakraborty R, Schull WJ, Schulsinger F. An adoption study of human obesity. N Engl J Med 1986;314:193-198.
18. Stunkard AJ, Harris JR, Pedersen NL, McClearn GE. The body mass index of twins who have been reared apart. N Engl J Med 1990;322:1483-1487.
19. Bouchard C, Trembley A, Despres JP, et al. The response of long-term overfeeding in identical twins. N Engl J Med 1990;322:1477-1482.
20. Zhang YY, Proenca R, Marffei M, et al. Positional cloning of the mouse obese gene and its human homologue. Nature 1994;372:425-432.
21. Montague CT, Farooqi IS, Whitehead JP, et al. Congenital leptin deficiency is associated with severe early o
July 5th, 2005
Abstract
It is the position of the American Dietetic Association and Dietitians of Canada that appropriately planned vegetarian diets are healthful, nutritionally adequate, and provide health benefits in the prevention and treatment of certain diseases. Approximately 2.5% of adults in the United States and 4% of adults in Canada follow vegetarian diets. A vegetarian diet is defined as one that does not include meat, fish, or fowl. Interest in vegetarianism appears to be increasing, with many restaurants and college foodservices offering vegetarian meals routinely. Substantial growth in sales of foods attractive to vegetarians has occurred, and these foods appear in many supermarkets. This position paper reviews the current scientific data related to key nutrients for vegetarians, including protein, iron, zinc, calcium, vitamin D, riboflavin, vitamin B-12, vitamin A, n-3 fatty acids, and iodine. A vegetarian, including vegan, diet can meet current recommendations for all of these nutrients. In some cases, use of fortified foods or supplements can be helpful in meeting recommendations for individual nutrients. Well-planned vegan and other types of vegetarian diets are appropriate for all stages of the life cycle, including during pregnancy, lactation, infancy, childhood, and adolescence. Vegetarian diets offer a number of nutritional benefits, including lower levels of saturated fat, cholesterol, and animal protein as well as higher levels of carbohydrates, fiber, magnesium, potassium, folate, and antioxidants such as vitamins C and E and phytochemicals. Vegetarians have been reported to have lower body mass indices than nonvegetarians, as well as lower rates of death from ischemic heart disease; vegetarians also show lower blood cholesterol levels; lower blood pressure; and lower rates of hypertension, type 2 diabetes, and prostate and colon cancer. Although a number of federally funded and institutional feeding programs can accommodate vegetarians, few have foods suitable for vegans at this time. Because of the variability of dietary practices among vegetarians, individual assessment of dietary intakes of vegetarians is required. Dietetics professionals have a responsibility to support and encourage those who express an interest in consuming a vegetarian diet. They can play key roles in educating vegetarian clients about food sources of specific nutrients, food purchase and preparation, and any dietary modifications that may be necessary to meet individual needs. Menu planning for vegetarians can be simplified by use of a food guide that specifies food groups and serving sizes. J Am Diet Assoc. 2003;103:748-765.
Vegetarianism in perspective
A vegetarian is a person who does not eat meat, fish, or fowl or products containing these foods. The eating patterns of vegetarians may vary considerably. The lacto-ovo-vegetarian eating pattern is based on grains, vegetables, fruits, legumes, seeds, nuts, dairy products, and eggs but excludes meat, fish, and fowl. The lacto-vegetarian excludes eggs as well as meat, fish, and fowl. The vegan, or total vegetarian, eating pattern is similar to the lacto-vegetarian pattern, with the additional exclusion of dairy and other animal products. Even within these patterns, considerable variation may exist in the extent to which animal products are avoided.
People choosing macrobiotic diets are frequently identified as following a vegetarian diet. The macrobiotic diet is based largely on grains, legumes, and vegetables. Fruits, nuts, and seeds are used to a lesser extent. Some people following a macrobiotic diet are not truly vegetarian because they use limited amounts of fish. Some “self-described” vegetarians, who are not vegetarians at all, will eat fish, chicken, or even meat. Some research studies have identified these “self-described” vegetarians as semivegetarians and have defined semivegetarian as occasional meat eaters who predominately practice a vegetarian diet or those who eat fish and poultry but less than 1 time per week. Individual assessment is required to accurately evaluate the nutritional quality of the diet of a vegetarian or someone who says that they are vegetarian.
Common reasons for choosing a vegetarian diet include health considerations, concern for the environment, and animal welfare factors (5,6). Vegetarians also cite economic reasons, ethical considerations, world hunger issues, and religious beliefs as their reasons for following their chosen eating pattern.
Consumer trends
In 2000, approximately 2.5% of the US adult population (4.8 million people) consistently followed a vegetarian diet and affirmed that they never ate meat, fish, or poultry. Slightly less than 1% of those polled were vegans. According to this poll, vegetarians are most likely to live on the east or west coast, in large cities, and to be female. Approximately 2% of 6- to 17-year-old children and adolescents in the United States are vegetarians, and around 0.5% of this age group are vegan. According to a 2002 survey, about 4% of Canadian adults are vegetarian; this represents an estimated 900,000 people.
Factors that may affect the number of vegetarians in the United States and Canada in the future include an increased interest in vegetarianism and the arrival of immigrants from countries where vegetarianism is commonly practiced. Twenty to 25% of adults in the United States report that they eat 4 or more meatless meals weekly or “usually or sometimes maintain a vegetarian diet,” suggesting an interest in vegetarianism. Additional evidence for the increased interest in vegetarianism includes the emergence of animal rights/ethics courses on college and university campuses; the proliferation of Web sites, magazines and newsletters, and cookbooks with a vegetarian theme; and the public’s attitude toward ordering a vegetarian meal when eating away from home. More than 5% of those surveyed in 1999 said they always order a vegetarian meal when they eat out; close to 60% “sometimes, often, or always” order a vegetarian item at a restaurant.
Restaurants have responded to this interest in vegetarianism. The National Restaurant Association reports that 8 out of 10 restaurants in the United States with table service offer vegetarian entrees. Fast-food restaurants are beginning to offer salads, veggie burgers, and other vegetarian options. Many college students consider themselves vegetarians. In response to this, most university foodservices offer vegetarian options.
There has also been a growth in professional interest in vegetarian nutrition; the number of articles in the scientific literature related to vegetarianism has increased from less than 10 articles per year in the late 1960s to 76 articles per year in the 1990s. In addition, the main focus of the articles is changing. Twenty-five or more years ago, articles primarily had themes questioning the nutritional adequacy of vegetarian diets. More recently, the theme has been the use of vegetarian diets in the prevention and treatment of disease. More articles feature epidemiological studies, and fewer reports are case studies and letters to the editor.
There is a growing appreciation for the benefits of plant-based diets, defined as diets that include generous amounts of plant foods and limited amounts of animal foods. The American Institute for Cancer Research and the World Cancer Research Fund call for choosing predominantly plant-based diets rich in a variety of vegetables and fruits, legumes, and minimally processed starchy staple foods and limiting red meat consumption, if red meat is eaten at all. The American Cancer Society recommends choosing most food from plant sources. The American Heart Association recommends choosing a balanced diet with an emphasis on vegetables, grains, and fruits, and the Heart and Stroke Foundation of Canada recommends using grains and vegetables instead of meat as the centerpiece of meals. The Unified Dietary Guidelines developed by the American Cancer Society, the American Heart Association, the National Institutes of Health, and the American Academy of Pediatrics call for a diet based on a variety of plant foods, including grain products, vegetables, and fruits to reduce risk of major chronic diseases.
New product availability
The US market for vegetarian foods (foods like meat analogs, nondairy milks, and vegetarian entrees that directly replace meat or other animal products) was estimated to be $1.5 billion in 2002, up from $310 million in 1996. This market is expected to nearly double by 2006 to $2.8 billion. Canadian sales of meat analogs more than tripled between 1997 and 2001.
The ready availability of new products, including fortified foods and convenience foods would be expected to have a marked impact on nutrient intake of vegetarians. Fortified foods such as soymilks, meat analogs, juices, and breakfast cereals can add substantially to vegetarians’ intakes of calcium, iron, zinc, vitamin B-12, vitamin D, and riboflavin. Vegetarian convenience foods including veggie burgers and veggie dogs, frozen entrees, meals in a cup, and soymilk can make it much simpler to be a vegetarian today than in the past.
Vegetarian foods are readily available, both in supermarkets and in natural foods stores. About half of vegetarian foods volume is sold through supermarkets and about half through natural foods stores. Three-fourths of soymilk sales take place in supermarkets.
Public policy statements and vegetarian diets
The United States Dietary Guidelines state, “Vegetarian diets can be consistent with the Dietary Guidelines for Americans, and meet Recommended Dietary Allowances for nutrients.” They give recommendations on meeting nutrient requirements for those who choose to avoid all or most animal products. Some have said that implementation of the Dietary Guidelines can best be achieved by use of vegetarian and plant-rich diets. National food guides include some vegetarian options. Foods commonly eaten by vegetarians such as legumes, tofu, soyburgers, and soymilk with added calcium are included in a table accompanying the USDA’s Food Guide Pyramid. Canada’s Food Guide to Healthy Eating can be used by lacto and lacto-ovo-vegetarians. Health Canada has stated that well-planned vegetarian diets are supportive of good nutritional status and health.
July 5th, 2005
DSHEA broadened the regulatory definition of dietary supplements beyond essential vitamins, minerals, and amino acids, and even beyond other food constituents proposed to optimize nutrition. The definition includes, with some exceptions, any product intended for ingestion as a supplement to the diet, including vitamins, minerals, amino acids, herbs, botanicals, other plant-derived substances, and concentrates, metabolites, constituents, and extracts of these substances. Although regulated as dietary supplements, with associated labeling requirements that limit disease-related claims, some supplement products are marketed in third party “literature and information” for pharmacological, rather than nutritional, purposes, as “natural” treatments for diseases such as cancer, heart disease, AIDS, arthritis, diabetes and multiple sclerosis. Similar promotions make distinctions between nutritional and pharmacological properties especially difficult for some herbal products. Herbal teas are regulated as foods, and herbs promoted for pharmacological properties (in third party literature) may appear in products such as beverages, bars, and other foods.
Conventional foods and dietary supplements are not intended to treat disease. Dietitians’ recommendations should be for the purpose of improving nourishment (with essential nutrients as well as other potentially beneficial food components that may help prevent disease). For products intended to treat disease, registered dietitians must evaluate whether their academic preparation and scope of practice (including state licensing regulations for dietitians and other health care professionals) qualifies them to provide advice advocating the use of such products. Recommendations of dietary supplements to treat disease should be under a physician’s supervision, but dietitians must know about these products to help answer client questions, identify potential food and drug interactions, and document client use.
Dietetics professionals must recognize when to make appropriate medical referrals for the diagnosis and treatment of disease. For example, in the United States, St. John’s Wort (Hypericum) is marketed to help mood and depression. The supportive evidence for this product has been sufficient to justify several randomized, placebo-controlled, double-blind clinical trials now underway to evaluate the effectiveness of Hypericum in comparison with established antidepressant medications. At the same time, concerns have been raised about drug interactions with Hypericum, including the undesirable use of this supplement by HIV-infected patients treated with certain protease inhibitors. This product may be shown to be safe and effective under some conditions. But even though neighbors, friends, or sales personnel can recommend such a product, professional recommendations should be made only by professionals trained to differentially diagnose and treat depression, skills which are not in the training or scope of practice of dietetics.
Certain foods, statutorily classified as “medical foods” under the Food, Drug and Cosmetic Act (FDC Act), are intended and can be used as therapeutic dietary adjuncts to medical treatment. However, such products must provide a distinctive nutritional need that is related to the disease or medical condition that is based on sound science, and the products must be used under the care and advice of a physician. Formulas and foods that are low or absent in phenylalanine and oral rehydration solutions are examples of such medical foods.
July 5th, 2005
The attention of the nutrition community has traditionally focused on obtaining micronutrients in adequate amounts. Much less research information is available to set standards for the upper limits of safe intake. The Food and Nutrition Board was unable to set a UL for five of the first 17 nutrients reviewed, because studies on the presence of adverse effects from large doses of nutrients had not been conducted or were inadequate. It recommended that in the absence of a UL, “extra caution may be warranted in consuming levels above recommended intakes.”
Although suppliers often cite benefits of supplements, consumers must rely on other more objective sources, including dietetics professionals, to learn of possible risks. For instance, the two studies that found increased cancer risk with supplemental beta-carotene tested daily doses of 20mg or 30mg. Supplements containing at least 15mg beta-carotene are sold frequently, and without warnings to smokers. Excess beta-carotene from foods is unlikely, because beta-carotene from foods is less bioavailable than supplemental beta-carotene. While a UL was not set for beta-carotene, the DRI committee concluded, “beta-carotene supplements are not advisable for the general population.”
The toxicities of high doses of nutrients such as vitamins A, B-6, D, niacin, iron, and selenium are well established. Although vitamin A toxicity has occurred from eating the livers of carnivorous animals or large fish, most nutrient toxicities occur through supplementation. Cases of vitamin D toxicity, resulting in hypercalcemia and reduced bone mineral density, have been reported in osteoporosis patients using several nonprescription dietary supplements. Excessively high levels of serum calcium, serum 25 (OH) D and serum creatinine have been reported in individuals taking vitamin D supplements at levels of 50,000 IU for as little as six weeks. Hypervitaminosis D has been reported from inadvertent overfortification of vitamin D in milk. The UL for vitamins and minerals are as low as five times the recommended intake for vitamin D, and as high as 25 to 50 or more times the recommended intakes for vitamins C and E. Although the median amounts of nutrients taken by supplement users in a 1980 national survey were less than three to five times recommended intakes, five percent of supplement users took doses exceeding 25 times the recommended intakes for thiamin, riboflavin, and vitamins B-6, B-12, C, and E . Unfortunately, most recent national survey reports do not provide quantitative information about the use of specific supplements. Such quantitative information is planned for future government nutrition surveys, and will be especially important with current trends for increased self-supplementation as well as increased food fortification.
Large doses of vitamin A may be teratogenic. Because of this risk, the Food and Nutrition Board recommends avoiding supplementation with preformed vitamin A during the first trimester of pregnancy unless there is specific evidence of vitamin A deficiency. A study of 22,748 pregnant women found that women taking more than 10,000 IU preformed vitamin A had a greater risk of giving birth to babies with cranial neural crest defects. Such a risk in early pregnancy raises a need for caution about general vitamin and mineral supplement use by women capable of becoming pregnant. Such women should obtain 400µg of synthetic folic acid daily (in addition to food folate from a varied diet), without taking preformed vitamin A.
Iron supplements intended for other household members are a common cause of pediatric poisoning deaths in the United States. Beyond acute toxicity, iron in moderate doses may have deleterious effects for some people. Unlike childbearing age women, who are more likely at risk of low iron stores or even iron deficiency, adult men and postmenopausal women generally have adequate to high iron stores. The additional iron commonly found in multivitamin and mineral supplements is unlikely to benefit them, and high iron stores may increase the risk of chronic disease in some individuals, especially the 12–14% of the population of Northern European decent who are heterozygous for hemochromatosis, an iron storage disease.
Dietary supplements can cause problems related to nutrient excesses, nutrient imbalances, or adverse interactions with medical care. Many of the problems associated with high doses of a single nutrient may reflect interactions that result in a ‘‘relative deficiency” for another nutrient. High doses of vitamin E can interfere with vitamin K action and enhance the effect of coumarin anticoagulant drugs, and high calcium intakes inhibit the absorption of iron and possibly other trace elements. Folic acid can mask the hematological signs of vitamin B-12 deficiency, and may exacerbate the irreversible neurological damage resulting from untreated vitamin B-12 deficiency. Folic acid can also adversely interact with anticonvulsant medications. Zinc supplementation may reduce copper status, impair immune responses, and decrease plasma HDL cholesterol. Little research has been done to address nutrient interactions and to determine how complex nutrient combinations in supplemental quantities will affect the absorption and utilization of each.
July 5th, 2005
Food fortification of commonly consumed foods may be a reliable and effective way to attain health benefits by increasing the nutrient intake of a population without relying on individual supplementation practices. However, fortification of the food supply must be moderated to benefit people who need to increase their nutrient intakes without increasing the risk of excessive intakes to others. For instance, because increasing folic acid consumption by either dietary selections or supplementation depends on personal behavioral change, food fortification with folic acid is an effective way to moderately increase folate intake for the entire population. New fortification standards for cereal grain products have increased folate intakes of the population, such that median folate intakes from all sources (expressed as dietary folate equivalents) are now estimated to exceed 400µg/d. However, women capable of becoming pregnant must use additional specific supplemental or fortification sources to meet the new recommendations of 400µg of folic acid from synthetic sources in addition to food folate from a varied diet. This recommendation cannot be met by general fortification of bread and cereal products without risking excessive folate intake that may mask or exacerbate vitamin B-12 deficiency or adversely interact with anticonvulsant or methotrexate medications in other population groups, especially children. From national food survey data, the Food and Drug Administration (PDA) estimates that 20–30% of young children (ages 1–8 y) may exceed the UL for folic acid, because of the frequent use of fortified breakfast cereals, fortified grain products, and dietary supplements. In some instances the preponderance of many products fortified with the same nutrient may make supplementation unnecessary or undesirable.
The US government sets standards of identity for enrichment or fortification of designated foods with specific amounts of nutrients such as thiamin, niacin, riboflavin, folic acid, and iron in grain products; vitamins A and D in milk; and iodine in salt. Fortification following these standards has made important contributions to nutrient intakes in the United States. The FDA food fortification policy warns that random fortification of foods could result in over- or underfortification and nutrient imbalances. The FDA indicates that it is not appropriate to fortify fresh produce, meat, poultry or fish products, sugars, or snack foods such as candies and carbonated beverages.
Food producers often initiate voluntary food fortification. In many instances, such as the fortification of some nondairy foods with calcium, or of vegetable-based meat substitutes with nutrients commonly supplied by meat, this voluntary food fortification can expand the food choices available to consumers to meet dietary recommendations. However, supplier-initiated food fortification should not reduce consumer choices by limiting access to unfortified foods. It is currently difficult for people concerned about excessive dietary iron to choose a breakfast cereal unfortified with iron. Similar difficulties may arise with the increasingly extensive calcium fortification of foods. Some foods seem to be fortified without an explicit public health rationale. The nutrients provided by both fortified foods and supplements change rapidly, and dietetics professionals must be aware of the changing market when assessing the total dietary intake of clients. Nutrient databases must be updated regularly to reflect these changes. In giving dietary advice, dietetics professionals should present clients with a number of options regarding food selection choices, including fortified foods, as well as supplementation choices. Again, the goal should be to meet dietary recommendations without exceeding the UL, and clients should be aware that there is no known benefit to exceeding the dietary recommendation.
For example, it is possible to meet the new calcium recommendations with regular use of (low-fat) dairy products. But for clients who, for whatever reason, limit their use of dairy products, dietetics professionals can help them determine whether the use of calcium-fortified orange juice and bread, or use of a calcium supplement can best fit their lifestyle to meet their calcium needs. For some people, a combination of using dairy products, fortified foods, and supplements would cause them to exceed the UL of 2500mg calcium daily. Dietetics professionals should help educate clients and the general public on the variety of fortified and supplemental products that would promote adequate without excessive intakes.
Marketplace fortification can substantially change the nutrient content of the food supply. For example, high iron enrichment standards in effect in the mid-to-late 70s were reduced because of concerns about efficacy and safety and have not changed since 1983. Yet the iron content of the food supply has continued to rise, because of an increased percentage of white flour that is enriched, an increased iron-fortification of breakfast cereals, and an increased use of grains.
Use of iron compounds for enrichment and fortification increased considerably in the last quarter of the century, with greater use of more bioavailable forms than in the past. This increase in food iron may pose a health risk for persons with a genetic risk of high iron stores. Fortification is commonly used to sell new food products. FDA’s fortification policy encourages and supports the rational addition of nutrients to foods. However, unlike the standards for iron enrichment of flour, bread or cereal (originally intended to replace nutrients lost in refinement of flour), there is currently no regulatory limitation on the amount of iron that can be added to many food products that do not have standards of identity.
The Canadian government has developed policy recommendations for the addition of vitamins and minerals to foods that suggest the use of mandatory food fortification programs for nutritional problems of public health significance that cannot be addressed through voluntary means. An additional recommendation would expand the range of food products that are fortified. It is further recommended that the addition of vitamins and minerals to foods not be permitted when no adequate nutritional rationale is provided.
July 5th, 2005
Should dietetics professionals advise general multivitamin-mineral supplements at modest doses to help meet dietary recommendations? As already indicated, a variety of good foods wisely selected is the basis of a nutritious diet, will meet dietary recommendations for most nutrients, and is the best way to assure a balance of nutrients and healthy food components for which no recommendations have been established. While there is little scientific evidence of benefit to the average person, there is also little evidence of harm from low-dose multivitamin or multivitamin-mineral supplements in amounts that do not exceed 100% of the RDA. The choice of either a multivitamin or highly fortified foods (such as some breakfast cereals) can be used to meet the new recommendations to increase synthetic sources of folic acid for women capable of becoming pregnant and synthetic sources of vitamin B-12 for older adults. Otherwise, recommendations for these groups can be met by using specific supplements providing folic acid or vitamin B-12, respectively.
Low-dose multivitamin-mineral supplements may provide benefit to those with limited dietary intakes. Such low-dose supplements improved indices of immune function and reduced infectious illness in a double-blind placebo-controlled investigation of 96 free-living Canadian elderly men and women. Similar supplements had no benefit in a double-blind placebo-controlled study of muscle weakness and physical frailty of 100 very elderly people in a Boston nursing home. More research in this area should be encouraged.
Professional recommendations to use low-dose multivitamin and mineral supplements should depend on individualized dietary assessments that consider how usual diets can be modified with food, fortification or supplemental sources of nutrients to meet individual needs. People using both highly fortified foods and multivitamins, even without other specific nutrient supplements can easily consume 300% of the RDA for many known nutrients. Some would question whether these high intakes of known nutrients are appropriately balanced with other health promoting components of food, many of which are unidentified. The goal should be to meet the RDA or AI while not exceeding the UL. As indicated by the Food and Nutrition Board, “there is no established benefit for healthy individuals if they consume a nutrient in amounts above the recommended intake (RDA or AI)”.
There is a special need for moderation under certain circumstances. For example, preformed vitamin A should not be taken in the first trimester of pregnancy. For men and postmenopausal women, who generally have adequate iron stores, supplemental iron, without a clinical assessment demonstrating low iron status, has little likelihood of benefit and may be of risk to those with certain genetic characteristics (see section on Toxicities, adverse nutrient interactions, and safety, p.x). In addition to evaluating total intakes for meeting and not greatly exceeding the Recommended Dietary Allowances, dietetics professionals should use the new UL designated by the Food and Nutrition Board to avoid dangerously excessive intakes.
July 5th, 2005
The latest recommendations from the Food and Nutrition Board, for the first time, include recommendations that supplements or fortified foods be used to obtain desirable amounts of some nutrients. Research demonstrated that the risk of bearing children with neural tube defects was reduced by folic acid supplementation. This and related research led to the recommendation that women capable of becoming pregnant obtain 400µg of synthetic folic acid daily from either fortified foods or a supplement in addition to consuming food folate from a varied diet (1). It is not known whether lower amounts of synthetic folic acid, or an equivalent amount of folic acid from food would provide a similar protective effect. However, it is known that food folate is not as well absorbed as synthetic folic acid and that to assess folate intake, adjustments must be made for bioavailability. Further research should help clarify this question.
Atrophic gastritis is a condition that reduces the absorption of food-bound vitamin B-12. Because 10–30% of persons older than 50 years have atrophic gastritis, the recommendation for this age group is to obtain vitamin B-12 from supplements or fortified foods.
The new recommendations for calcium, 1300mg for 9–18 year olds, 1000mg for 19–50 year olds, and 1200mg for adults greater than 51 years of age, are considerably greater than previous recommendations (800mg for adults) and average US calcium intakes (approximately 700-800mg). Because there was not adequate research data available to determine an EAR or RDA for calcium, the new calcium recommendations are listed as Adequate Intakes. Although such recommendations can be met with generous consumption of (low fat) dairy products, some people may prefer to meet the recommendations with fortification or supplemental sources of calcium.
Meeting the new AI for vitamin D will likely require supplemental sources of vitamin D for the elderly if they do not drink generous quantities of fortified milk. Individualized dietary assessment and counseling can help identify those who are able to obtain recommended levels of calcium and vitamin D from dietary (and sunlight) sources, and those who may benefit from fortified foods or supplements.
When dietary selection is limited, nutrient supplementation can be useful to meet dietary recommendations. Examples include supplemental vitamin B-12 for strict vegans who eliminate all animal products from the diet; vitamin D for those with limited milk intake and sunlight exposure; calcium supplements and/or calcium fortified foods for those with lactose intolerance or allergies to dairy products; and a multivitamin and mineral supplement for those following severely restricted weight-loss diets (eg, <1200kcal/day).
Iron supplementation during pregnancy is routinely practiced in the United States. Two expert committees have called for more research concerning whether iron supplementation should occur routinely or only on the basis of individual iron status assessment. A Food and Nutrition Board committee recommended further study into the possibility of adverse outcomes at very low or high hemoglobin levels, but concluded that the practice of routine iron supplementation should not be changed without further research, a conclusion confirmed by a more recent expert group.
In many areas the research evidence remains equivocal or incomplete. However, recent recommendations from the Food and Nutrition Board provide a useful indication of unbiased, well-considered scientific judgements from nutrition experts. This current evaluation of the available scientific research does not support the efficacy of supplement doses greater than the RDA for such nutrients as vitamin C, vitamin E, or selenium that are commonly marketed for the prevention of chronic disorders such as heart disease or cancer. Randomized, placebo-controlled trials with vitamin E supplementation have not provided evidence of harm, but neither have they provided consistent evidence of effectiveness in prevention of cancer or cardiovascular disease. As new research becomes available, recommendations must be based on a careful consideration of the total scientific literature.
July 5th, 2005
According to recent representative national surveys (partly representing conditions before DSHEA), approximately 40 to 47% of the US population use vitamin or mineral supplements at least occasionally. Slightly more than two thirds of supplement users take only one supplement, generally a multiple vitamin with or without minerals. Current, reliable data are not available to adequately describe the amounts of specific nutrients consumed as supplements. Moreover, supplement use may be commonly underreported or inaccurately reported, especially when determined through self-administered questionnaires. Consistent with earlier reports, recent data indicate greater supplement usage among Caucasians, women, older age groups, those with higher personal incomes, those with more education, and those living in the western United States. Several reports indicate that supplement users (whether they are daily or occasional users) also have higher intakes of nutrients from foods, lower dietary fat, and higher fruit, vegetable, and dietary fiber consumption. Although these differences vary according to gender, age, and ethnicity, the greater nutrient intakes among supplement users, compared with nonusers, persist after adjusting for income, education, employment status, age, sex and ethnicity. Use of supplements has been positively associated with a lower body mass index, with agreement that “eating a variety of foods each day gives you all the vitamins and minerals you need,” with more frequent exercise, with self-described excellent or very good personal health, with not smoking, not drinking heavily, and believing that diet affects disease.
Because many of the lifestyle characteristics of supplement users are health related, unless studies test nutrient and other supplements in comparison with placebos, randomly and blindly assigned to volunteers that are otherwise similar, health benefits observed in such studies cannot be reliably attributed to supplement use.
The Need for Strong Scientific Evidence Based on Controlled Clinical Trials
Epidemiological studies show associations, but are not able to establish cause-and-effect because they do not control for other diet and lifestyle variables. These variables may also influence the results and may not be evident or even suspected. Cause-and-effect relationships can be most conclusively tested with prospective, randomized, double-blind, placebo-controlled supplementation trials. Such trials control for confounding variables by randomly assigning the supplement to participants, who are otherwise identically treated and evaluated by investigators. These experiments are generally better controlled with supplements rather than dietary changes, both because they require fewer and simpler behavioral changes and because the treatment can easily be blinded from both participants and investigators. Such studies must be conducted to provide firm research support for the safety and efficacy of dietary supplements.
As an example, although high fruit and vegetable consumption increases dietary and blood beta-carotene levels, controlled investigations with beta-carotene supplementation were needed to determine whether it accounted for the reduction in cancer risk that is associated with fruit and vegetable intake. Three randomized placebo-controlled trials prospectively investigated whether beta-carotene supplements would reduce cancer incidence. None of these three trials found beneficial effects of beta-carotene in reducing cancer incidence. Unexpectedly, in the two studies that included smokers or workers exposed to asbestos, beta-carotene supplementation resulted in a higher incidence of lung cancer and of total mortality in these participants. The third study, which involved US physicians, found no harm but no benefit from beta-carotene supplementation. The reason for the adverse effects is unclear. One potential explanation is that beta-carotene supplements increase blood levels to a greater degree than an equal amount of beta-carotene in food. Supplements may have different (either higher or lower) bioavailability and may affect body stores differently than foods, and more is not necessarily better. In supplemental amounts, beta-carotene may interfere with the intestinal absorption of other potentially beneficial related compounds, such as canth-axanthin, lutein, and lycopene. Or, especially in the lungs of smokers, large amounts of beta-carotene may be readily oxidized into pro-carcinogenic products. Only randomized, controlled supplementation trials were able to detect the pro-carcinogenic effect of beta-carotene in smokers. Before these studies, beta-carotene was widely considered safe, because there were no harmful short-term adverse effects, even with very high doses.
In addition to giving considerably greater acceptance to the results of randomized controlled trials and recognizing the limitations of descriptive observations, evaluations of the research literature should look for reproducibility of results. Rarely can a single study stand alone as scientific confirmation of a hypothesis. Results obtained from some groups may not be representative of results in other populations (eg, benefits observed in a developing country may not apply to a better-nourished Western population). Results may differ with age and gender. Beneficial effects may require longer studies or more sensitive testing. Conclusions are strengthened when the research measures the true functional or disease endpoints of interest, rather than intermediate biomarkers (eg, fracture incidence vs bone density; or initial myocardial infarction vs platelet aggregation). Similarly, conclusions drawn from experimental work in vitro, in cell-culture or in animal models should not be the basis for using dietary supplements without confirmation in controlled human studies.
In helping consumers with questions about dietary supplement claims, dietetics professionals can readily access an online database of medical research literature (eg, Medline) to determine the amount and kinds of scientific research available and select more in-depth reading as appropriate to the situation. As an example, a recent Medline search for chromium picolinate produced 76 citations. The list was reduced to 16 by searching for chromium picolinate and placebo. Of these, eight described placebo-controlled research on the effects of chromium picolinate on body composition: five found no effect, two found beneficial effects and one found an effect in women but not in men. Although additional reading is necessary to make valid conclusions about the relevance and quality of each study, this quick comparison suggests that the beneficial claims for this supplement have not been fully supported by research evidence. The Federal Trade Commission, which regulates the advertising of dietary supplements, has taken action against unsubstantiated weight loss and health benefit claims for chromium picolinate. Unfortunately, an Internet search also rapidly demonstrates that related claims continue to abound.
July 5th, 2005
A common concern of consumers is that typical diets are unlikely to provide adequate amounts of vitamins and minerals. However, nationally representative surveys indicate that median US nutrient intakes meet or exceed recommendations for several nutrients (protein, vitamin C, thiamin, riboflavin, niacin, and phosphorus) without dietary supplements.
Caution must be applied in interpreting reported intakes that are less than recommended, as survey results likely underestimate true dietary intakes because of limitations in dietary assessment methodology. Self-reported food intakes (the basis of national survey data) commonly underestimate true food intakes by approximately 20%, as indicated by comparing reported energy consumption with measurements of energy expenditure using doubly labeled water techniques. Although we do not know whether the underestimation of all nutrients is proportional to the underestimation of energy, the foods that are underreported are unlikely to be completely nutrient free. Some vitamins and minerals may be further underestimated because nutrient databases have not kept up with recent increases in food fortification.
While survey results indicate that median intakes of several vitamins and minerals are 70–80% of recommended amounts, these data are of questionable reliability because median energy intakes are similarly low in the same survey. In contrast, there is considerable related evidence that US energy intakes are not generally inadequate: the incidence of obesity in the United States has been increasing, 31.7% of adults are overweight, only 6% believe that their diet is “too low in calories”, only 3.3% of the population indicate that there is sometimes, and 0.6% indicate that there is often not enough food. While food insufficiency is a concern even when it occurs in small segments of the population, it is also clear that the deficit in surveyed energy intakes, and likely the intakes of other nutrients, is unreliable.
Concerns about median intakes also apply to the distribution of energy and nutrient intakes. The distribution of nutrient intakes is even more difficult to accurately determine, in part because a distribution of nutrient intakes from two independent days of recalls is much wider than the distribution of chronic usual nutrient intakes. Promoters of nutrient supplements often cite USDA data indicating the percentage of US adults consuming less than recommended amounts of nutrients. However, the USDA survey also shows that 45% of US adults meet less than three-fourths of the recommended amount of energy, an estimate that is clearly unreliable. Although they provide the best data available, dietary surveys provide inexact data, not just for individual intakes, but for group averages and distributions, that are not a sound basis to justify uniform supplementation of diets in the United States with vitamins and minerals.
The clinical assessment of vitamin and mineral status does not generally support inadequacies that may be implied from dietary survey data. For several nutrients, such as magnesium or zinc, sensitive indicators of marginal nutritional status are unavailable, and there is no well-accepted evidence either of deficiency in the population or of beneficial effects of supplemental intakes. For other nutrients, clinical and biochemical indices do not support concerns about insufficiency raised by the dietary data. For example, although median intakes of vitamin A in adults are below RDA values, the prevalence of low serum levels of vitamin A is very small, and there is evidence of deleterious effects of high levels of supplementation in some instances.
As another example, the recently increased RDA for Vitamin E (15mg/d for healthy adults) is well above NHANES III and CSFII survey mean estimated intakes of about 9.4 and 6.4mg alpha-tocopherol daily from food for men and women, respectively. The report explaining the new RDA emphasizes that these survey data likely underestimate true intakes because of measurement error, and that the “mean intakes of apparently healthy adults in the US and Canada are likely to be above the RDA of 15mg/d of alpha-tocopherol”. In addition, more than 95% of the US population meet or exceed the plasma alpha-tocopherol concentrations used as the criterion for the new estimated average requirement. Thus, even the relatively large discrepancy between the RDA and dietary survey data does not justify vitamin E supplementation.
The new DRI recommendations identify several circumstances when increased nutrient intake would be beneficial for some population groups (see Circumstances when nutrient supplementation is indicated,p.x). When dietary intakes do not meet science-based dietary recommendations, food fortification and dietary supplementation can make an important contribution. However, dietary supplements are not necessarily formulated to fill the gaps between nutrient intakes from food sources and nutrient recommendations such as the RDA or AI .
July 5th, 2005
During the 1990s, the Food and Nutrition Board of the Institute of Medicine, National Academies of Science, in conjunction with Health Canada, began a thorough evidence-based review of nutrient requirements and their associations with health outcomes. In an ongoing process, Dietary Reference Intakes (DRI) are being established for each of the nutrients and other food constituents judged by expert groups as likely to have health effects. The Food and Nutrition Board determines Estimated Average Requirements (EAR), and Recommended Dietary Allowances for each nutrient based on specific functional outcomes. When EARs are not available from published research data, adequate intakes (AI) are suggested, rather than RDAs. In addition, tolerable upper intake levels (UL) are provided in the DRI for the first time. Information on various risks associated with insufficient and excessive amounts of nutrients or food components is summarized with the DRIs. In addition, the various functional outcomes appropriate for each age group are evaluated for each nutrient or food component, and the rationale for choosing a specific outcome is provided. This extensive evidence-based documentation provides a strong scientific rationale for recommendations to reach stated goals safely and effectively with respect to health.
The Dietary Guidelines for Americans issued by the US Department of Agriculture (USDA) and Department of Health and Human Services, the USDA Food Guide Pyramid, the FDA’s Nutrition Facts Label, and other label information on most processed foods provide useful public guidance for choosing a variety of foods for good health. These guides emphasize the consumption of grain products, vegetables, and fruits, moderate use of meats and low fat dairy products, and sparing use of fats and sweeteners. Good nutrition primarily depends on appropriate food choices. Consuming a wide variety of foods in moderate amounts reduces the risk of inadequate and excessive intakes.
July 5th, 2005
There are several reasons why relying on foods is usually the best strategy for optimal nourishment. Research on the relationship between diet and disease has indicated that both macro- and micronutrients are important and has documented the need to avoid dietary excesses and imbalances as well as insufficient nutrient intakes. Some food components, such as dietary fibers, have potential health benefits but are not easily incorporated into supplements. Many unidentified constituents that may have important health benefits are contained in the complex matrix of natural foods. Nutrient-nutrient, drug-nutrient, and other interactions are also important and may affect health; high doses of one nutrient or food constituent may affect the absorption or metabolism of others. These concerns underscore the conclusion that nutrition cannot be optimized simply through fortification or supplementation of the food supply. Wise food choices are also essential and provide the necessary foundation of optimal diets.
Much remains unknown about the biologically active components in food. Research has identified numerous compounds other than essential nutrients in plant and animal foods (phytochemicals and zoochemicals, respectively), with chemical properties or biological effects that suggest health benefits (5). Other natural food constituents may have adverse effects. Because there are so many constituents in foods, it is difficult to specifically identify those responsible for positive health effects observed in epidemiological or clinical studies. There may be more than one active substance, and the matrix in which they appear may also be important. Moreover, standards for characterizing some of these constituents may be lacking. Extracts of the compounds may differ from the forms that appear in foods in physiologically important ways, and the bioavailability of many of the compounds is unknown.
There is no scientific basis for the common assumptions that if a small amount of a food component is beneficial, then more must be better, or that concentrated amounts of a limited number of components will provide greater benefits than the combination of the many different constituents provided by food. For example, a variety of natural pesticides produced by plants to ward off predators have anticarcinogenic properties (6). While these natural pesticides in small amounts may function by preconditioning the body’s detoxification systems, they may not be safe or effective when concentrated and taken in larger doses as supplements (6). Concentrated amounts of single substances may also adversely affect the absorption, biological transport, and metabolism of other potentially beneficial substances with similar chemical properties (7,8). In addition, synthetic forms of some nutrients may not be as effective; for some nutrients such as amino acids, only the L(levo)- form, and not the D(dextro)- and L(levo)- forms, are utilized, and supplements providing both D(dextro)- and L(levo)- forms have low bioavailability. Other synthetic forms may be more bioavailable than the forms in food and may provide greater risk of toxicity or imbalance.
Studies with animals demonstrate the inadequacy of present nutrition knowledge to artificially formulate diets that optimize health in all respects and in all cells, tissues, and organ systems. Scientists know much more about the nutritional requirements of rats than of any other species. Semi-purified diets containing casein, starch, cellulose, corn oil, minerals, and vitamins have been formulated to meet all known requirements to optimize rat growth and health. However, rats fed these semi-purified diets are still at greater risk of developing cancer than those fed commercial “crude” diets containing components such as grain, beet pulp, alfalfa meal, cane molasses, and fish meal (9). These observations suggest that all of the numerous potentially beneficial components of foods, let alone the appropriate amounts and combinations, have not yet been identified.
While researchers have repeatedly observed health benefits associated with high fruit and vegetable consumption, it has not been possible to identify a specific constituent or, more likely, combinations of several constituents acting in concert that may be responsible for these benefits (10,11). Research results are still too incomplete to make sound evidence-based recommendations for specific amounts of individual constituents or combinations of them at present. Given our incomplete knowledge, eating a wide variety of foods is the best way to obtain adequate amounts of beneficial food constituents, while avoiding chemical excesses or imbalances. Supplements and fortified foods can then be used to meet dietary recommendations if dietary patterns still fall short of Recommended Dietary Allowances (RDA) or Adequate Intake Levels (AL) for normal, healthy people. Supplements or fortified foods can also be useful if other factors, such as abnormal absorption, increased requirements, or excessive losses of nutrients or other physiologic abnormalities suggest a science-based need for supplements or fortified foods.
July 5th, 2005
Abstract
Wise food choices provide the necessary foundation for optimal nutrition. Science has not fully identified the specific chemical components that account for the benefits of healthy eating patterns. Selection of a variety of foods, using tools such as the USDA/HHS Dietary Guidelines for Americans and the USDA Food Guide Pyramid, is the best way to provide a desirable balance, without excessive intakes of macronutrients, micronutrients and other beneficial components of foods. Nevertheless, for certain nutrients and some individuals, fortification, supplementation, or both may also be desirable. Nutrient intakes from all these sources should be considered in dietary assessments, planning and recommendations. The recommendations of the National Academy of Sciences’ Food and Nutrition Board provide a sound scientific basis for vitamin and mineral intakes. Intakes exceeding those recommendations have no demonstrated benefit for the normal, healthy population. Dietetics professionals should base recommendations for use of fortified foods or supplements on individualized assessment and sound scientific evidence of efficacy and safety. It is the position of the American Dietetic Association that the best nutritional strategy for promoting optimal health and reducing the risk of chronic disease is to wisely choose a wide variety of foods. Additional vitamins and minerals from fortified foods and/or supplements can help some people meet their nutritional needs as specified by science-based nutrition standards such as the Dietary Reference Intakes (DRI) J Am Diet Assoc. 2001; 101:115–125
Introducton
Dietary supplements are a timely topic today in the research, legislative, business, and consumer arenas. As a growing number of epidemiological studies point to the importance of diet and nutrition to optimize health and prevent disease, additional scientific research has addressed the potential benefit of supplementing diets with vitamins or minerals. Large, randomized, double-blind supplementation trials have demonstrated positive health benefits of some supplements, but uncertainty with respect to the health effects of others, and ineffectiveness or adverse effects of still others. The National Institutes of Health (NIH) has created an Office of Dietary Supplements to gather information on these substances. For the first time, the Food and Nutrition Board of the National Academy of Sciences has recommended fortified or supplemental nutrient sources to increase the bioavailability of specific vitamins—for example, vitamin B-12 and folic acid— for certain population groups that have altered absorption or very high nutrient needs (1). Today, dietary supplements are heavily marketed and promoted, and consumers can choose from an unprecedented variety of foods, fortified foods, and dietary supplements. Dietetics professionals must carefully evaluate the emerging science, while giving consumers accurate, current advice upon which they can make informed decisions.
The dietary supplement industry has grown rapidly. Total sales of dietary supplements in 1998 have been estimated at $13.9 billion, up from approximately $8.6 billion in 1994 (2). Of these, 40% represent vitamins and 8% minerals. The remainder consists of herbal and botanical supplements, sports supplements, and other specialty products, totaling 29,000 different products (2). Changes in government regulations associated with the Dietary Supplement Health and Education Act (DSHEA) have restricted the role of the Food and Drug Administration (FDA) in the regulation of dietary supplements and associated label claims (3). Media coverage of adverse events associated with some of these products has raised concerns on the part of the public and health professionals that the industry is insufficiently regulated and that some of these products are unsafe (4). New federal legislation about supplement labeling and health claims, including a broadened definition of “dietary supplements,” has increased the need for dietetics professionals to learn more about these products to better help consumers make informed decisions based on sound scientific knowledge. This intense scientific, regulatory, and popular interest provides a dynamic climate for this American Dietetic Association position on the role of food fortification and dietary supplements, with special emphasis on vitamin and mineral supplements, in promoting health.
POSITION STATMENT
It is the position of the American Dietetic Association (ADA) that the best nutritional strategy for promoting optimal health and reducing the risk of chronic disease is to wisely choose a wide variety of foods. Additional vitamins and minerals from fortified foods and/or supplements can help some people meet their nutritional needs as specified by science-based nutrition standards such as the Dietary Reference Intakes (DRI).
July 5th, 2005
Conclusion
Achieving and maintaining healthy lifestyle behaviors including activity and food intake can help weight management by helping to prevent weight gain. Prevention of weight gain and achieving modest amounts of weight loss can improve overall health.
In today’s society, the environment is conducive to less activity than previous decades, more food availability in larger quantities, and higher caloric density. Therefore, concentrating on factors to limit the environmental influences is critical. It is important to acknowledge those factors we can change and those we cannot. It is also important that dietitians and other health care providers be in the forefront of lobbying for public health policy, third party reimbursement for treatment and management, and adequate community resources to address weight status and weight-related illness. We need to document our outcomes, develop flexible and individualized goals for patients, and continue to support research efforts to improve the efficacy of treatment. Such documentation requires thorough assessments and follow-up: medically, nutritionally, be-haviorally, and psychologically. Based on current available treatment approaches, goals need to stay focused on a “healthy lifestyle” targeting the environmental factors that allow for gene expression, particularly physical activity and food choices directed toward less calorically dense foods.
We must educate ourselves and the medical community as to the physical and psychological impact of our recommendations. We must include our patients in the decision making process and inform them of the known positive outcomes they can achieve.
ADA Position adopted by the House of Delegates October 20, 1996, and reaffirmed on September 12,1999. This position is in effect until December 31, 2005. The American Dietetic Association authorizes republication of the position paper, in its entirety, provided full and proper credit is given. Requests to use portions of the position must be directed to ADA Headquarters at 800/877-1600, ext 4835 or ppapers@eatright.org.
Recognition is given to the following for their contributions:
Authors:
Sue Cummings, MS, RD (Massachusetts General Hospital Weight Center, Boston, MA); EUen S. Parham, PhD, RD (Northern Illinois University, DeKalb, IL); Gladys W. Strain, PhD, RD (Mt. Sinai School of Medicine, New York, NY)
Reviewers:
Gaston P. Bathalon, PhD, RD, FADA (US Army, Natick, MA); Ann M. Coulston, MS, RD, FADA (nutrition consultant, Woodside, CA); Sharron Dalton, PhD, RD (New York University, New York, NY); Dayle Hayes, MS, RD (nutrition consultant, Billings, MT); Joanne P. Ikeda, MA, RD (University of California, Berkeley, CA); Melinda Manore, PhD, RD (Oregon State University, Corvallis, OR)
Members of the Association Positions Committee Workgroup: Barbara Baron, MS, RD (Chair); Mary Marian, MS, RD; Lillie Williams, PhD, RD, FADA; James 0. Hill, PhD (content advisor)
References
1. US Department of Health, Human Services, Center for Disease Control and Prevention; National Center for Health Statistics, Maryland. Prevalence of Overweight and Obesity Among Adults: United States, 1999.
2. Wolf AM, Colditz GA. Current estimates of the economic cost of obesity in the United States. Obes Res 1998;6:97-106.
3. Allison DB, Fontaine KR, Manson JE, Stevens J, Vanltallie TB. Annual deaths attributable to obesity in the United States. JAMA 1999;282:1530-1538.
4. Dheeksha M. National Institute of Health, National Heart, Lung, and Blood Institute Clinical guidelines on the identification evaluation, and treatment of overweight and obesity in adults—the evidence report. Obes Res 1998;6:121S-122.
5. Anderson JW, Kontz EC, Frederich RC, Wood CL. Long-term weight-loss maintenance: a meta-analysis of US Studies. Am J Clin Nutr 2001;74:579-584.
6. Schick SM, Wing RR, Klem ML, McGuire Tetal. Persons successful at long-term weight loss and maintenance continue to consume a low energy, low fat diet. JADA 1998;98:408-413.
7. Wing RR, Hill JO. Successful weight loss maintenance. Ann Rev Nutr 2001;21:323-341.
8. Kassirer JP, Angell M. Losing weight—An ill-fated New Year’s Resolution. N Engl J Med 1998;338:52-54.
9. National Institutes of Health and National Heart, Lung and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults—The Evidence Report. Obes Res. 1998:xi.
10. Leibel R, Rosenbaum M, Hirsch J. Changes in Energy Expenditure Resulting from Altered Body Weight. N Engl J Med 1995;332:621-628.
11. Schwartz MW, Woods SC, Porte D, Seeley RJ, Baskin DG. Central nervous system control of food intake. Nature 2000;404:661-671.
12. Bray GA, York DA. Clinical review 90: Leptin and clinical medicine: a new piece in the puzzle of obesity. J Clin Endocrinol Metab 1997;82:2771-2776.
13. Erlanson-Albertsson C, York D. Enterostatin—a peptide regulating fat intake. Obes Res 1997;5:360-372.
14. Barsh G, Farooqi I, O’Rahilly S. Genetics of body weight regulation. Nature 2000;404:644-651.
15. Perusse L, Chagnon YC, Weisnagel SJ, Rankinen T, Snyder E, Sands J, Bouchard C. The human obesity gene map: The 2000 Update. Obes Res 2001;9. 8135–169.
16. Maes HH, Neale MC, Eaves IJ. Genetics and environmental factors in relative body weight and human adiposity. Behav Genet 1997;27. 325–35.
17. Stunkard AJ, Sorensen TIA, Hanis C, Teasdale TW, Chakraborty R, Schull WJ, Schulsinger F. An adoption study of human obesity. N Engl J Med 1986;314:193-198.
18. Stunkard AJ, Harris JR, Pedersen NL, McClearn GE. The body mass index of twins who have been reared apart. N Engl J Med 1990;322:1483-1487.
19. Bouchard C, Trembley A, Despres JP, et al. The response of long-term overfeeding in identical twins. N Engl J Med 1990;322:1477-1482.
20. Zhang YY, Proenca R, Marffei M, et al. Positional cloning of the mouse obese gene and its human homologue. Nature 1994;372:425-432.
21. Montague CT, Farooqi IS, Whitehead JP, et al. Congenital leptin deficiency is associated with severe early onset obesity in humans. Nature 1997;387:903-908.
22. Friedman JM, Halaas JL. Leptin and the regulation of body weight in mammals. Nature 1998;395:763-770.
23. Ravussin E, Bogardus C. Relationship of genetics, age, and physical fitness to daily energy expenditure and fuel utilization. Amer J Clin Nutr 1989;49. 968–75.
24. Bradford BL, Spiegelman BM. Towards a molecular understanding of adaptive thermogenesis. Nature 2000;404:652-660.
25. Bray GA.ContemporaryDiagnosis, Management of Obesity Health Care Co.Newtown, PA: 1998. 35-67.
26. Mokdad AH, Serdula MK, Dietz WH, Bowman BA, Marks JS, Koplan JP. The spread of the obesity epidemic in the United States, 1991-1998. JAMA 1999;282:1519-1522.
27. Casas YG, Schiller BC, DeSouza CA, Seals DR. Total and regional composition across age in healthy Hispanic and white women of similar socioeconomic status. Am J Clin Nutr 2001;73:13-18.
28. Jakicic JM, Wing RR. Differences in resting energy expenditure in African Americans vs Caucasian overweight females. Int J Obes Relat Metab Disord 1998;22. 236–42.
29. Hill JO, Peters JC. Environmental contributions to the obesity epidemic. Science 1998;280:1371-1374.
30. Young LR, Nestle M. The contribution of expanding portion sizes to the US obesity epidemic. Am J Public Health 2002;92:246-249.
31. Devlin MJ, Yanovski SZ, Wilson GT. Obesity: What mental health professionals need to know. Am J Psychiatry 2000;157:854-866.
32. Stahl SM. How to appease the appetite of psychotropic drugs. J Clin Psychiatry 1998;59:500-501.
33. Ackerman S, Nolan LJ. Body weight gain induced by psychotropic drugs: incidence, mechanism, and management. CNS Drugs 1998;9:135-151.
34. DiPietro L, Anda RF, Williamson DF, Stunkard AJ. Depressive symptoms and weight change in a national cohort of adults. IntJ Obes 1992;16:745-753.
35. Stunkard AJ, Fernstrom MH, Frank E, Kupfer DJ. Direction of weight change in recurrent depression: consistency across episodes. Arch Gen Psychiatr 1990;47:857-860.
36. Wurtman RJ, Wurtman JJ. Serotoninergic mechanisms and obesity. J Nutr Biochem 1998;9:511-515.
37. Dheeksha M. National Institutes of Health and National Heart, Lung and Blood Institute Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults—The Evidence Report. Obes Res 1998;6:108S-109S.
38. Willett WC, Dietz WH, Colditz GA. Primary Care: Guidelines for healthy weight. N Engl J Med 1999;341:427-434.
39. Kuczmarski RJ, Flegal KM. Criteria for definition of overweight in transition: background and recommendations for the United States. Am J Clin Nutr 2000;72:1074-1081.
40. Flegal KM, Troiano RP, Ballard-Barbash R. Aim for a healthy weight: What is the target. J Nutr 2001;131:440S-450S.
41. Bray GA. Clinical Evaluation and Introduction to Treatment of Overweight Contemporary Diagnosis and Management of Obesity, Handbooks in Health Care Co, Newtown, PA 1998.
42. Dheeksha M. National Institutes of Health and National Heart, Lung and Blood Institute. Clinical Guidelines on the Identification Evaluation and Treatment of Overweight and Obesity in Adults—The Evidence Report. Obes Res 1998;6:54S.
43. World Health Organization. Obesity: Preventing and Managing the Global Epidemic. Report of a WHO Consultation on Obesity, Geneva, June 1997. 1998, pp 43-72.
44. Cummings S, Pratt J, Kaplan L. Evaluation and Management of Obesity. In: Carlson K, Eisenstat S. Primary Care of Women. 2nd ed. New York, NY: Mosby Yearbook; 2002.
45. Yanovski SZ, Nelson JE, Dubbert BK. Spitzer Rl. Association of binge eating disorder and psychiatric comorbidity in obese subjects. Am J Psychiatry 1993;150:1472-1479.
46. Molijari E, Ragazzoni P, Morosin A. Psychopathology in obese subjects with and without binge-eating disorder and in bulimic subjects. Psychol Rep 1997;80:1327-1335.
47. Dheeksha M, National Institutes of Health and National Heart, Lung and Blood Institute.. Clinical Guidelines on the Identification, evaluation and treatment of Overweight and Obesity in Adults—The Evidence Report. Obesity Research, 1998;6:110S.
48. Bertram SR, Venter I, Stewart RI. Weight loss in obese women—exercise vs dietary education. S Afr Med J 1990;78:15-18.
49. Gordon NF, Scott CB, Levine BD. Comparison on single versus multiple lifestyle interventions: are the antihypertensive effects of exercise training and diet-induced weight loss additive?. Am J Cardiol 1997;79:763-767.
50. Stefanick MI, Mackey S, Sheehan M, Ellsworth N, Haskell WL, Wood PD. Effects of the NCEP Step 2 diet and exercise on lipoprotein in postmeno-pausal women and men with low HDL-cholesterol and high LDL-cholesterol. N Engl J Med 1998;329:12-20.
51. Grommet J. Weight management: Framework for changing behavior In: Dalton S. Overweight and Weight Management. Gaithersburg, MD: Aspen; 1997.332-347.
52. Van Gaal LF. Dietary treatment of obesity. In Handbook of Obesity, eds Bray GA, Bouchard C and James WPT. Marcel Dekker, NY 1998, 875-890.
53. McFarlane T, Polivy J, McCabe RE. Help, not harm: Psychologic foundation for a nondieting approach toward health. J Social Issues 1999;55:261-276.
54. Dheeksha M, National Institutes of Health and National Heart, Lung and Blood Institute.. Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity in Adults—The Evidence Report. Obes Res 1998;6:110S.
55. Foster GD, Wadden TA, Vogt RA, Brewer G. What is a reasonable weight loss Patients?’ expectations and evaluations of obesity treatment outcome. J Consult Clinl Psychol 1998;65:79-85.
56. Allison D. A Handbook of Assessment Methods for Eating Behaviors and Weight-related Problem: Measures Theory and Research, Sage, Thousand Oaks CA 1995.
57. St Jeor ST. Obesity Assessment: Tools, Methods and Interpretations. NY: Chapman &. Hall. 1997.
58. Parham ES. Promoting body size acceptance in weight management counseling. JADA 1999;99:920-925.
59. Strain GW. Response to promoting size acceptance to weight management counseling. JADA 1999;99:926-928.
60. Lyons P, Miller WC. Effective healthcare for large people. Healthy Weight J 2000;14:71-73.
61. Berg F. Women Afraid to Eat: Breaking Free in Today’s Weight Obsessed World. Hettinger ND: Healthy Weight Network; 2000.265-282.
62. Kant AK. Consumption of energy-dense, nutrient-poor foods by adult Americans: nutritional and health implications The third National Health and Nutrition Examination Survey, 1988-1994. Am J Clin Nutr 2000;72:929-936.
63. Dheeksha M. National Task Force on the Prevention and Treatment of Obesity, National Institutes of Health. Very low-calorie diets. JAMA 1993;270:967-974.
64. Wadden TA. Treatment of obesity by moderate and severe caloric restriction: results of clinical research trials. Ann Intern Med 1993;119. 688–93.
65. . NIH Technology Assessment Conference Panel, 1993. Methods for voluntary weight loss and control: Technology Assessment Conference Statement. Ann Intern Med 119:764-770.
66. In Contemporary Diagnosis and Management of Obesity, ed Bray G. Handbooks in Health Care Co, Newtown, Pa 1998, 192-202.
67. Wadden TA, Foster GD, Letizia KA. One-year behavioral treatment of obesity: comparison of moderate and severe caloric restriction and the effects on weight maintenance therapy. J Consult Clin Psychol 1994;62:165-171.
68. Stein K. High-protein, low carbohydrate diets: Do they work?. JADA 2000;100:760-761.
69. United States Dept of Agriculture.Dietary Guidelines for Americans, 2000. 5th ed. 2000 Home and Garden Bulletin 232; 28-31.
70. National Institutes of Health and National Heart, Lung and Blood Institute.. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults—The Evidence Report 1998;6:114S.
71. Flechtner-Mors M, Ditschuneit HH, Johnson TD, Suchard MA, Adler G. Metabolic and weight loss effects of long-term dietary intervention in obese patients: Four year results. Obes Res 2000;8:399-402.
72. Wadden TA, Frey DL. A multicenter evaluation of a proprietary weight loss program for the treatment of obesity: A five-year follow-up. Int J Eat Disord 1997;22:203-212.
73. Freedman MR, King J. Kennedy Popular diets: a scientific review. Obes Res 2001;9:1S-40S.
74. Rippe JM. Hess St The role of physical activity in the prevention and management of obesity. J Am DietAssoc 1998;98:S31-S38.
75. Mclnnis KY. Exercise and obesity. Coron Artery Dis 2000;11:111-116.
76. Pavlou KN, Krey S, Steffee WO. Exercise as an adjunct to weight loss and maintenace in moderately obese subjects. Am J Clin Nutr 1989;49:1115-1123.
77. Schulz LO, Schoeller DA. A compilation of total daily energy expenditures and body weights in healthy adults. Am J Clin Nutr 1994;60:676-681.
78. Bailor DL, Katch VL, Becque MD, Marks CR. Resistance weight training during caloric restriction enhances lean body weight maintenance. Am J Clin Nutr 1988;319:1173-1179.
79. Porcari J, Ward A, Morris D, Maher M, Cuneo P, O’Hanley S, Rippe J. Comparison of weight loss in males and females after 16 weeks of fitness walking and/or diet [abstract]. Med Sci Sports Exers 1986;21:S102.
80. Ross R, Dagnone D, Jones PJH, Smith H, Paddags A, Hudson R, Janssen I. Reduction in obesity and related comorbid conditions after diet-induced weight loss or exercise-induced weight loss in men. Ann Intern Med 2000;133:92-103.
81. Mourier A, Gautier JF, De Kerviler E, Bigard AX, Villette JM, Gamier JP, Duvallet A, Guezennec CY, Cathelineau G. Mobilization of visceral adipose tissue related to the improvement in insulin sensitivity in response to physical training in NIDDM. Effects of branched-chain amino acid supplements. Diabetes Care. 1997;20:385-391.
82. Wing RR, Matthews KA, Kuller LH, Meilahn EN, Plantinga P. Waist to hip ratio in middle-aged women: Associations with behavioral and psychosocial factors and with changes in cardiovascular risk factors. Arterioscler Thromb Vase Biol 1991;11:1250-1257.
83. Blair SN, Kampert JB, Kohn HWsrd, Barlow CE, Macera CA, Paffenbarger RS J, Gibbon LW. Influences of cardiorespiratory fitness and other precursors on cardiovascular disease an all-cause mortality in men and women. JAMA 1996;276:205-210.
84. Bartlow CE, Kohl HW, Gibbons LW, Clair SF. Physical fitness, mortality, and obesity. Int J Obesity 1995;19:S41-S44.
85. Wood P, Stefanick M, Dreon D, Frey-Hewitt B, Garay SC, Williams PT, Superko HR, Fortmann SP, Albers JJ, Branizan KM, Willsworth NM, Terry RB, Haskell WL. Changes in plasma lipids and liproproteins in overweight men during weight loss through dieting as compared with exercise. N Engl J Med 1988;319:1173-1179.
86. Yanovski S, Yanovski JA. Drug Therapy: Obesity. N Engl J Med 2002;346:591-602.
87. NIH, NAASO. The Practical Guide: Identification, Evaluation, and Treatment of Overweight and Obesity in Adults. NIH Publication Number DO-4084, 2000. 35-38.
88. Stein, K. Herbal supplements and prescription drugs. JADA. 2000; 1 00:4.
89. Nortier JL, Martinez M-CM, Schmeiser HH, Arlt VM, Bieler CA, Petein M, Depierreux MF, DePauw L, Abramowicz D, Vereerstraeten P, Vanherweghem J-L. Urothelial carcinoma associated with the use of a Chinese herb (Aristolochia Fangchi). N Engl J Med 2000;342. 1686–92.
90. Kernan WN, Viscoli CM, Brass LM, Broderick JP, Brott T, Feldman E, Morgenstern LB, Wilterdink JL, Horwitz Rl. Phenylpropanolamine and risk of hemorrhagic stroke. N Engl J Med 2000;343. 1686–92.
91. Haller CA, Benowitz NL. Adverse cardiovascular and central nervous system events associated with dietary supplements containing ephedra alkaloids. N Engl J Med 2000;343. 1833–8.
92. National Institutes of Health and National Heart, Lung, and Blood Institute.. Clinical Guidelines on the Identification, Evaluation and Treatment of Overweight and Obesity — The Evidence Report. Obes Res1 1998;6:120S.
93. Campbell LA, Smith FJ, Burn P. Strategies and potential molecular targets for obesity treatment. Science. 1998; 1383-1387.
94. Heymsfield SB, Greenberg AS, Fujioka K, Dixon RM, Kushner R, Hunt T, Lubina JA, Patane J, Hunt P, McCamish M. Recombinant leptin for weight loss in obese and lean adults. A randomized, controlled, dose-escalation trial. JAMA 1999;282:1568-1575.
95. MacLean LD, Rhode BM, Nohr CW. Late outcome of isolated gastric bypass. Ann of Surg 2000;231:524-528.
96. Marceau P, Hould FS, Simard S, et al. Biliopancreatic diversion with duodenal switch. World J Surg 1998;22:947-954.
97. MacLean LD, Rhode BM. Does genetic predisposition influence surgical results of operations for obesity?. Obes Surgery 1996;6:132-137.
98. Kellum JM, DeMaria EJ, Sugarman HJ. The surgical treatment of morbid obesity. Curr Prob Surg 1998;35:791-858.
99. Sumall AJ. A review of liposuction as a cosmetic surgical procedure. J Nat Med Assn 1987;79:1275-1279.
100. Miller WC. How effective are traditional dietary and exercise interventions for weight loss?. Med Sci Sports Exerc 1999;31:1129-1131.
101. Dheeksha M. National Institute of Health, National Heart, Lung, and Blood Institute Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults — the evidence report. Obes Res 1998;6:111S.
102. National Institute of Health,National Heart, Lung, and Blood Institute.. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults — the evidence report. Obes Res 1998;6:127S.
103. Marlatt GA, Gordon JR. Relapse Prevention: Maintenance Strategies in Addictive Behavior Change, Guilford Press, NY 1985.
104. Wing RR. Behavioral approaches to the treatment of obesity In: Bray GA, Bouchard C, James WPT, Handbook of Obesity. New York, NY: Marcel Dekker; 1998. 855-1999874.
105. Wadden TA. The management of obesity: From past failure to future attainment In: Guy-Grand B, Ailhaud G, Progress in Obesity Research 8. London: John Libbey &. Co; 1999. 713-719.
106. Jeffery RW, Drewnowski A, Epstein LH, Stunkard AJ, Wilson GT, Wing RR, Hill DR. Long-term maintenance of weight loss: current status. Health Psychology 2000;1:5-16.
107. International Classification of Diseases. 9th Rev. ICD-9-CM. Chicago, IL: American Medical Association; 2000.
108. National Institutes of Health and National Heart, Lung and Blood Institute. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults—The Evidence Report. Obes Res. 1998:xii.
109. Byfield C. A lifestyle physical activity intervention for obese sedentary women: Effect on cardiovascular disease risk factors. American College of Sports Med: Indianapolis IN; 2000.
110. Helm KK, Klawiller B. Nutrition Therapy: Advanced counseling Skills. Lake Dallas, Texas: Helm Seminars; 1995. 135-161.
111. Beck JS. Cognitive Therapy-.Basics and Beyond, Guilford Press, New York, NY 1995.
112. Rosen JC. Improving body image in obesity. In: Thompson, JK, Body Image, Eating Disorders and Obesity. Washington, DC: American Psychological Association; 1996. 425-550.
July 5th, 2005
Responsibilities of Dietitians in Weight Management
Dietetic practice in weight management is complex and challenging; specialized training is desirable. It is important to focus upon long-term as well as short-term outcomes while respecting the patient’s goals and values. Since many patients are looking for fast and large weight losses, it is important to convey realistic expectations. Tracking treatment outcomes and sharing these with patients, help to clarify expectations at the outset. It is also important for dietitians to maintain currency in their own professional development; including continuing education and training and, if feasible, obtaining specialized supervision when needed. Dietetic professionals need to stay within appropriate scope of practice; they must know their limitations and respect them; making referrals as needed.
Role of the Dietetics Professional in a Team Approach to Weight Management
The physician is usually the first member of the health care team to see patients in need of weight management. It is essential that physicians use this contact effectively, reflecting the complexity of the challenge and making referral to other health care professionals to activate successful intervention. The dietitian has primary responsibility for assessment and recommendations related to food behavior. Given the relationship of physical activity to energy expenditure and weight maintenance, the dietitian may also be involved in assessment and recommendation of activity, provided the patient is cleared for exercise by his or her medical doctor. For example, Byfield was able to show significant and sustained improvements in energy expenditure and cardiorespiratory fitness in heavy women who participated in a program designed to address barriers to exercise and encourage daily physical activity (109).
It may also fall on the dietitian to be the provider who can interpret the results from the initial assessment and make appropriate, patient-matched treatment recommendations.
The dietitian should be attentive to the patient’s concerns, being aware of feelings, values, behaviors, and worries beyond food behaviors and assume an active role in communicating these to the other care providers.
Dietitians are the primary nutrition practice professionals and, as such, have a responsibility for exerting leadership for reducing the prevalence of obesity. Clearly prevention is a complex matter requiring the cooperation of private and public sectors. Currently there is no clear path of action to prevent excessive body weight, which increases health risks. Research has identified certain groups at particular risk; evidently interventions have to start with very young children (26,110).
Dietitians can contribute to the prevention of obesity, not only in their own practice but also by pointing out the seriousness of the increasing weight of the entire population. Dietitians must advocate public policies to support increased opportunigties for healthy eating, exercise, and research into improved strategies for intervention and prevention. As professionals with daily close contact with individuals struggling with weight management, dietitians need to remind policy makers of the difficulty and complexity of the situation. They must resist efforts to further stigmatize obesity, pointing out the lack of evidence of any benefit of this approach, as well as the danger of increasing the risk of eating disorders. It has been suggested that successful weight management is in need of fresh ideas (93); dietitians with their broad educational preparation and intense patient contact may be a rich source of such ideas.
Knowledge and Skills Required
A thorough knowledge of weight management and appreciation of its complexity is imperative. The dietitian will benefit from a working knowledge of theories of behavior change and how to build upon these in designing interventions. Weight management requires the dietitian to have specialized assessment and screening skills in order to make appropriate treatment recommendations. When providing counseling it is important to involve the patient as an active partner. In addition to nutrition education and guidance, nutrition counseling strategies include cognitive-behavioral interventions (111,112). These interventions often involve the ability to assist patients in finding resources within themselves and their community so as to continue behaviors independent of continued intervention by health care professionals.
July 5th, 2005
Pharmacotherapy
Currently there are few pharmacotherapy options available for long term usage. Medications that have been approved by the PDA for treatment of “clinically significant” obesity (BMI > 30 or BMI 27-29 with one or more obesity-related disorders.), include sibutramine and orlistat. Sibutramine (Meridia) is a centrally acting serotonin and adrenergic reuptake inhibitor. It has the potential complication of hypertension and increased heart rate. Orlistat (xenical) is a pancreatic lipase inhibitor which inhibits the absorption of up to 30% of dietary fat. Steatorrhea, bloating and distension, and anal leakage are potential complications, and one must be alert for possible fat-soluble vitamin deficiencies. Reported losses with these medications combined with a low-calorie diet average 2-10kg per year, and if the medications are discontinued weight gain results (86). Amphetamine-like derivitives: mazindol, phentermine, benzphetamine, phendimetrazine are available only for short-term use. When weight loss drugs are prescribed they should be only as part of a comprehensive treatment plan including behavior therapy, diet, and physical exercise (87). The herbal preparations for weight loss do not have standardized amounts of active ingredients and have been reported to have harmful effects (88,89). Certain over-the-counter preparations containing propanolamine (Dexatrim and related compounds) have no proven efficacy for short- or long-term weight loss and are being recalled because of the incidence of hemor-rhagic stroke (90,91). Ephedrine plus caffeine, and fluoxetine have been tested for weight loss, but not approved and over-the-counter and herbal preparations are currently not recommended (92).
Pharmacotherapy research is currently focusing on three approaches, a) inhibitors of energy intake (appetite suppressants, orexins/hypocretin antagonists); b) enhancers of energy expenditure, UCP2 and UCP3 uncoupling proteins; and c) stimulators of fat mobilization (93). Leptin is now in the process of phase 2 testing, but to date, data do not indicate leptin has the potential for being the much sought after magic bullet to modify weight status (94).
Surgery
During the past 25 years, gastric surgery has been shown to be the most effective approach for generating long-term weight loss in extremely heavy persons. More than 90% of patients experience significant (> 20% to 25%) weight loss, and between 50% and 80% maintain weight loss for over 5 years; in contrast, the 5-year efficacy of other approaches is approximately 5% (95). Surgical procedures promote weight loss both by restricting food intake and causing malabsorption. Food intake may be reduced by the placement of a band (gastric banding), which allows only a small amount of food to enter the stomach or by the placement of a band plus staples to create a small pouch (vertical banded gastroplasty). Gastric bypass operations, Roux-en-Y gastric bypass, and the extensive gastric bypass (biliopancreatic diversion, with duodenal switch), create a small pouch by stapling or removal of portions of the stomach, and also bypass the duodenum and other segments of the small intestines thus producing some extent of malabsorption. These procedures have acceptable operative risk, 1% to 2.5% death rate, but require lifelong medical follow-up and monitoring to avoid and manage possible complications (4). Although bariatric surgery has made major advancements in the last 30 years, the effect on the human body of the weight loss produced requires investigation.
Prior to surgery, patients should be fully evaluated by a multidisciplinary team, including but not limited to a medical doctor, psychiatrist, and a dietitian. The role of the dietitian is important in screening to evaluate weight history, efforts to lose weight, food preferences, and food related behaviors, ie, binge eating to assist in electing the optimal procedure for the patient. The patient should be motivated to accept the responsibility for sustaining lifestyle changes to maintain weight loss and decrease post-operative complications.
The development of laparoscopic techniques has significantly reduced the frequency of complications with wound infection, which was the most common complication (5% to 20%), and the length of hospital stay. Data is available for a 5-year follow-up for standard open procedures but long-term follow-up of laparoscopic procedures is not yet available (96). It is of note that surgery appears to rule over genetics in weight loss responses and maintenance (97).
Accepted indications for surgical weight loss therapy are having a BMI > 40 or BMI 35-39 with one or more obesity-related disorders; and having previously unsuccessful non-surgical attempts at long-term weight management. Weight loss surgery is most effective when accompanied by pre- and post-operative comprehensive therapy to modify eating and exercise behavior. Such adjunctive therapy increases the likelihood of long-term success and should be a standard component of surgical weight management (98).
Liposuction is another form of surgery with a focus on adipose tissue. Its purpose is cosmetic, to alter body contours, and it should not be considered as a surgical procedure for weightless (99).
Relapse Prevention
Clearly, preventing regain of fat losses is the major challenge of weight maintenance. Among the limited numbers of programs that do long-term follow-up, many find that losses are completely regained within 3-5 years (100). A successful program is often defined as one that produces maintenance of loss of at least 5%, or 6.6kg of body weight (101). NIH recommends that maintenance efforts be continued indefinitely (102). Dietary and physical activity modifications need to be integrated and accepted as a way of life.
Unfortunately, we have limited knowledge of what behaviors are necessary for successful maintenance. The National Weight Control Registry involves individuals who have lost at least 30 pounds and sustained the loss for a least a year; the typical registrant has, in fact, lost more than that minimum and sustained the loss for more than five years. The successful maintainers in the Registry report very careful attention to a reduced calorie, low-fat diet, increased levels of physical activity, and frequent weighing (5–7). It is not established that these behaviors represent what is minimally necessary for weight loss maintenance; however, these proposed lifestyle modifications on an ongoing basis have produced long-term weight loss maintenance.
Experts in the prevention of relapse have developed models to explain the environmental, emotional, and behavioral aspects of relapse (103). Unfortunately, these models do not address the biological factors impacting metabolic rate and hunger and satiety, thereby contributing to weight regain. Improvements in weight loss maintenance are shown when the risks of relapse are addressed as part of the intervention. Even with extended contacts and relapse prevention education, the reported programs are not able to produce maintenance of all losses in all participants (104). It is difficult to sustain the commitment and participation in long-term treatment programs or with follow-up programs (105), but this is what has been shown to be effective.
Dietitians, because of their close work with patients and clients, are ideally placed to exert leadership in combating weight management relapse. In every patient interaction, they should emphasize the goal of long-term change. Dietitians may help their patients come to view dealing with their weight as a multi-stage process. Regain should not be framed as a personal failure but rather as an indication of a need for another phase of active management. Not all patients will be able to maintain the behaviors that are necessary to sustain losses. Dietitians can anticipate this reality and help their patients to salvage some benefits from their efforts.
Dietitians should address the problems by collecting data initiating alternative strategies and using other resources in the community. An ongoing problem continues to be the cost of providing expanded and extended programs. Currently there is no funding for long-term maintenance services. We must find creative new ways to exert our influences. These might be online programs, phone contacts, utilization of lay leadership, and others.
Cost of Weight Management
Although ideally a long-term, multidisciplinary program is more effective than a short-term program (106), ideal programs are expensive to run. Multifaceted programs can better address the complexity of issues related to achievement of goals; these programs require the services of several health care professionals, increasing the financial cost and time commitment from patients. In addition, access to exercise facilities and/or equipment and purchasing more appropriate food may add to to the overall expense. All approaches to weight management, including pharmaceutical and surgical interventions, ultimately require a comprehensive lifestyle program that focuses on nutrition, exercise, cognitive behavioral changes and medical monitoring to increase the likelihood of long-term success and healthy outcomes.
However, there currently exist barriers to implementing lifestyle programs of maximum effectiveness. Even though health care costs are acknowledged, and NHLBI and the International Classification of Diseases list obesity as a disease, many other organizations do not consider it a disease for reimbursement purposes (9,107). For example, third party reimbursement is not universal and rare for programs to modify weight status; reimbursement when it is provided is frequently limited in duration. Since the prevalence of obesity is rapidly increasing and becoming a major public health concern, it is imperative that private and public sectors work together to obtain third party reimbursement to support treatment for changes in weight status for obesity treatment as well as funding for further research. Obesity must be acknowledged as a disease for reimbursement purposes since data clearly support its association with increased morbidity and mortality (108). Until such data is accepted by both third party payers and the medical community, the obesity epidemic will not be effectively controlled, and a significant barrier will be maintained. Also, there is limited understanding among both lay and health care professionals of the complexity and difficulty of the need for intensive and extensive weight management support. Cost-containment strategies that may improve efficiency may also compromise outcome. These strategies include: triage or stepped approaches; limitations of treatment length and/or frequency of sessions; use of groups; and/or coordination with self-help, lay-led, and for-profit resources.
July 5th, 2005
Previous Posts