Weight loss nutritional supplements

Abstract

Obesity is a major public health concern in the United States and is related to a considerable number of chronic diseases including hypertension, type 2 diabetes, stroke, heart disease, degenerative joint disease, and several types of cancer. Because of the medical implications and health-care costs associated with obesity, as well as the negative social and psychological impacts, many individuals turn to nonprescription nutritional weight loss supplements hoping for a quick fi x, and the weight loss industry has responded by offering a variety of products that generates billions of dollars each year in sales. Most nutritional weight loss supplements are purported to work by increasing energy expenditure, modulating carbohydrate or fat metabolism, increasing satiety, or blocking fat or carbohydrate absorption. To review the literally hundreds of nutritional weight loss supplements available on the market today is well beyond the scope of this chapter. Therefore, several of the most commonly used supplements were selected for critical review, and practical recommendations are provided based upon the fi ndings of wellcontrolled, randomized clinical trials that examined their effi cacy. In the majority of cases, the nutritional supplements reviewed either elicited no clinically meaningful effect (i.e., ≥5 % change in body weight) or resulted in changes in body weight and composition that are similar to that which occurs through a restricted diet and exercise program. There is evidence to suggest that herbal forms of ephedrine, such as ma huang, combined with caffeine or caffeine and aspirin (i.e., ECA stack) are effective for inducing moderate weight loss in overweight adults. However, because of the ban on ephedra, it is not practical to recommend it for weight loss, and ephedra-free supplements, such as bitter orange, do not appear to be as effective. Green bean coffee extract, capsaicinoids, and white kidney bean extract ( Phaseolus vulgaris ) do appear to hold some promise as possible adjuvant treatments for weight loss; however, most dietary weight loss supplements used alone or in combination are largely ineffective.