CHAPEL HILL, N.C. — Weight loss supplements can be found in the health aisles of most grocery and drug stores, but do they really work? According to one recent, diet pills are a waste of money and could be dangerous.
They’re marketed as being able to boost metabolism, burn fat and blunt appetite. However, there is “a lack of strong evidence” weight loss pills actually work, say scientists at the University of North Carolina. Perhaps more concerning is that misleading claims “have the potential to harm patients,” they warn.
The findings may alarm millions of women hoping to get “beach body ready” for the summer.
“Our findings are important for clinicians, researchers and industry alike. They suggest the need for rigorous evaluation of products for weight loss. Only then can we produce data that allows clinicians to provide input and advice with a higher degree of certainty to our patients,” says corresponding author John Batsis, a nutritionist at the university, in a statement.
Weight loss supplement industry is thriving, but research raises doubts
There are hundreds of weight loss supplements in an industry worth billions. They range from cabbage and green tea extract to the shellfish sugar chitosan, guar gum and conjugated linoleic acid. One in three Americans trying to lose weight have used one, researchers note.
The analysis by The Obesity Society (TOS) reviewed hundreds of existing studies. Most showed users failed to shed the pounds. Batsis suggests manufacturers work with academics to design high quality clinical trials.
Patients often struggle to lose or maintain weight because therapies approved by the Federal Drug Administration (FDA) are ineffective. It is also difficult to access healthcare professionals who provide treatments for obesity. The National Institutes of Health’s Office of Dietary Supplements now evaluates information and stimulates and supports research.
TOS decided it was important to examine non-FDA therapies to guide its membership by pooling data on 315 randomized controlled trials. Only 52 were found to be at low risk of bias and sufficient to support efficacy. Of these, just 16 demonstrated significant before and after differences compared with dummy pills.
Weight loss ranged widely from 10.5 ounces to nearly 11 pounds, say researchers. TOS’ Clinical Committee, led by Dr Srividya Kidambi who co-authored the study, recommended doctors consider the findings when advising patients.
“Public and private entities should provide adequate resources for obesity management. We 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,” adds Dr Kidambi, of the Medical College of Wisconsin.
The supplements tend to be prescribed by doctors, in combination with diet and exercise, to people who have a significant amount of weight to lose – typically a BMI (body mass index) of 27 or higher, but some experts have called for them to be banned.
The study is published in Obesity, in the flagship journal of The Obesity Society.
South West News Service writer Mark Waghorn contributed to this report.