Weight-loss supplements typically fall into 1 of 4 categories depending on their hypothesized mechanism of action: products that block the absorption of fat or carbohydrate, stimulants that increase thermogenesis, products that change metabolism and improve body composition, and products that suppress appetite or give a sense of fullness. Each category is reviewed, and an overview of the current science related to their effectiveness is presented. While some weight-loss supplements produce modest effects (<2 kg weight loss), many have either no or few randomized clinical trials examining their effectiveness. A number of factors confound research results associated with the efficacy of weight-loss supplements, such as small sample sizes, short intervention periods, little or no follow-up, and whether the supplement is given in combination with an energy-restricted diet or increased exercise expenditure. There is no strong research evidence indicating that a specific supplement will produce significant weight loss (>2 kg), especially in the long term. Some foods or supplements such as green tea, fiber, and calcium supplements or dairy products may complement a healthy lifestyle to produce small weight losses or prevent weight gain over time. Weight-loss supplements containing metabolic stimulants (e.g., caffeine, ephedra, synephrine) are most likely to produce adverse side effects and should be avoided.
Dietary Supplements for Improving Body Composition and Reducing Body Weight: Where Is the Evidence?
Melinda M. Manore
Markers of Bone Health, Bone-Specific Physical Activities, Nutritional Intake, and Quality of Life of Professional Jockeys in Hong Kong
Eric Tsz-Chun Poon, John O’Reilly, Sinead Sheridan, Michelle Mingjing Cai, and Stephen Heung-Sang Wong
of forced vomiting and reliance on appetite suppressants; Wilson et al., 2014a ). It is of paramount importance to consider how the current lifestyle practices of jockeys and the associated consequences may impact on their general well-being. The purpose of this study therefore was to assess markers