New Dietary Supplements for Obesity

The prevalence of obesity has continued to increase over the last several years in the world. Per the National Health and Nutrition Examination Survey (NHANES) for the 2007-2008 year, the prevalence of obesity, defined as a body mass index (BMI) ≥ 30 kg/m2, among adults was greater than 30% and those who were overweight or obese (BMI ≥ 25 kg/m2) was almost 70% for both men and women. The trend over the past 20 years has shown an increase in the prevalence of obesity of six to seven percent every 10 years. In addition, health care costs are approximately 42% higher for obese patients when compared to normal-weight patients. Dietary supplements for weight loss are marketed to offer patients improved success that is faster and easier than calorie reduction and increased exercise. Despite concerns with efficacy and safety, these products continue to be an appealing alternative or adjunct to weight management. Several mechanisms are proposed to differentiate how these products work. Despite widespread use, there is still limited data on the safety and efficacy of the products currently on the market. Because dietary supplements are viewed as food and not drugs, they are not regulated by the Food and Drug Administration (FDA). Instead, under the Dietary Supplement Health and Education Act (DSHEA), dietary supplements can be marketed without evidence to support efficacy and safety. If a dietary supplement appears to be unsafe after being marketed, the FDA can then decide whether or not to have the product removed from the market. This was the case for the weight loss supplement ephedra which was removed from the market in 2004 after reports of serious health risks. The literature published in the arena of weight loss continues to be plagued by concerns such as: small studies, inconsistency with participant body weight (BMI), variation in length of studies, use of exercise, and a variety of products at differing dosages. For this presentation, recently published randomized, placebo-controlled trials were identified in PubMed, MEDLINE, International Pharmaceutical Abstracts, Cochrane Database, and Google Scholar using the search terms dietary supplement, herbal, weight loss, obesity, and individual supplement names.Data for conjugated linoleic acid (CLA), Garcinia cambogia, chitosan, pyruvate, psyllium, White kidney beans Extract, apple cider vinegar and chia seed for weight loss were identified. CLA, chitosan, pyruvate, and Irvingia gabonensis appeared to be effective in weight loss via fat modifying mechanisms. However, the data on the use of these products is limited. Several mechanisms are proposed to differentiate how these products work. These include products that claim to be: fat blockers, lipotropics or fat busters, thermogenic or energy modifiers, and products that can change carbohydrate metabolism, water elimination, or the feeling of satiety or fullness. Conclusion. Many obese people use dietary supplements for weight loss. To date, there is little clinical evidence to support their use. More data is necessary to determine the efficacy and safety of these supplements. Healthcare providers should assist patients in weighing the risks and benefits of dietary supplement use for weight loss.