“Purported” weight-loss products –12 dietary supplements and 2 alternative therapies – lack high-quality evidence to back up claims of efficacy, a systematic review by the Obesity Society reports.
Most of the more than 300 published randomized controlled trials in the review were small and short, and only 0.5% found a statistically significant weight loss of up to 5 kg, John A. Batsis, MD, from the University of North Carolina at Chapel Hill, and colleagues reported in the journal Obesity.
“Despite the poor quality of these studies with high degrees of bias, most still failed to show efficacy of the product they were testing,” Srividya Kidambi, MD, from the Medical College of Wisconsin, Milwaukee, and colleagues from the Obesity Society’s Clinical Committee pointed out in an accompanying commentary.
“Yet these are the studies that are often used to support manufacturers’ claims of ‘clinically proven’ in their marketing,” they noted.
Most consumers, they continued, are unaware that these nondrug weight-loss products are not regulated by the Food and Drug Administration, but rather, if their ingredients are “generally regarded as safe,” they are treated as dietary supplements and require little or no testing to show either efficacy or safety.
“Our patients need to become aware that dietary supplements for weight loss are nothing more than a pipe dream, and as clinicians we would do well to talk with our patients and help steer them toward science-based treatments rather than the ‘Wild West’ of dietary supplements that are marketed for weight loss,” Scott Kahan, MD, MPH, coauthor of the review and commentary, told this news organization.
The dietary supplement industry has a strong lobby against legislation for more rigorous requirements for claims, noted Dr. Kahan, of the National Center for Weight and Wellness as well as George Washington University, Washington.
However, “there has to be some level of protection for consumers” who are faced with ads by “healthy skinny people saying this [product] can change your life.”
Clinical providers need to guide patients to “evidence-based interventions to support weight loss such as behavioral weight-loss interventions, [FDA-approved] medications, or bariatric surgery,” said Dr. Batsis, who also coauthored the commentary.
There is a “critical need” for more rigorous trials, and a partnership between researchers, funders, and industry, he added.
According to Dr. Kidambi and colleagues, “the use of these products will continue as long as they are allowed to be marketed with the aforementioned limited federal oversight and there is a lack of access to evidence-based obesity treatments.”
The commentary authors “call on regulatory authorities to critically examine the dietary supplement industry, including their role in promoting misleading claims and marketing products that have the potential to harm patients.”
They also urged public and private health insurance plans to “provide adequate resources for obesity management.”
And clinicians should “consider the lack of evidence for non–FDA-approved dietary supplements and therapies and guide their patients toward tested weight-management approaches.”