Weight loss supplements containing stimulants such as caffeine may not be effective in the long term, according to a new study. The researchers at Natural Standard have also evaluated the safety and effectiveness of various weight loss supplements with mixed findings.
In the recent study, weight loss supplements were evaluated based on four categories: supplements that block fat and carbohydrate absorption, supplements that increase heat production, supplements that produce changes in metabolism and supplements that decrease appetite. A comprehensive literature search was conducted to evaluate the available scientific evidence.
The study reported that high-quality clinical trials are lacking and that there is no strong evidence supporting the use of weight loss supplements for long-term results. They found that some foods and supplements, such as green tea and calcium supplements, may complement a healthy lifestyle, but that weight loss supplements may also pose a health risk, particularly those that contain caffeine and ephedra.
The study concluded that weight loss supplements may not be effective in the long term and some ingredients may potentially be harmful. More high-quality scientific studies are needed to better understand these results.
Research conducted by Natural Standard also suggests data are inconclusive for many weight loss herbs and supplements. There is currently strong scientific evidence that suggests ephedra may be effective in promoting weight loss. Ephedra contains the chemical ephedrine, which appears to cause weight loss when used in combination with caffeine, based on the available scientific evidence. The results of research on ephedrine alone without caffeine are unclear. The amounts of ephedrine in commercially available products have varied widely. Ephedra or ephedrine use have been associated with many safety concerns, including hypertension, tachycardia, CNS excitation, arrhythmia, myocardial infarction and stroke.
There is also good scientific evidence supporting the use of chitosan for weight loss. While some studies suggest that chitosan is an effective weight loss therapy, others have found it is ineffective. More research is needed.
For more information about integrative therapies with evidence of benefit for weight loss, please visit Natural Standard's Comparative Effectiveness Database.
For more information about ephedra, please visit Natural Standard's Foods, Herbs & Supplements Database.