Review Finds Minimal Evidence That Dietary Supplements Lead to Weight Loss

A metanalysis of 315 clinical trials of weight loss supplements and therapies published in Obesity found a lack of strong evidence that dietary supplements and alternative therapies help adults lose weight. According to the researchers, most of the studies reviewed found that the supplements analyzed did not produce weight loss among users.

The investigators conducted a systematic review of the existing literature using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines to evaluate the efficacy of dietary supplements and alternative therapies for weight loss in participants aged 18 and older. Searches of Medline (Pubmed), Cochrane Library, Web of Science, CINAHL and Embase (Ovid) were conducted to gather data.

The analysis focused on 315 peer-reviewed, randomized-controlled trials and analyzed them for risk of bias, ultimately classifying 52 studies as low-risk of bias and sufficient to support efficacy. Of these 52 studies, 16 were found to demonstrate significant pre/post intergroup differences in weight when compared to placebo. Weight loss across these studies varied from 0.3 kg to 4.93 kg.

“Our findings are important for clinicians, researchers, and industry alike as they suggest the need for rigorous evaluation of products for weight loss,” said John Batsis, MD, associate professor in the Division of Geriatric Medicine at the University of North Carolina (UNC) School of Medicine, and in the Department of Nutrition at the UNC Gillings School of Global Public Health, in a press release. “Only then can we produce data that allows clinicians to provide input and advice with a higher degree of certainty to our patients.”

According to the study authors, patients often struggle to lose or maintain weight either because of a lack of efficacy of existing FDA-approved therapies or a lack of access to health care professionals who provide treatments for obesity. They said that public and private entities should provide adequate resources for obesity management. Further, regulatory authorities should critically examine the dietary supplement industry to reduce misleading claims and halt the marketing of products that have the potential to harm patients.

REFERENCE

Review shows minimal, high-quality evidence dietary supplements lead to weight loss [news release]. EurekAlert; June 23, 2021. Accessed June 23, 2021. https://www.eurekalert.org/pub_releases/2021-06/tos-rsm061721.php