WEDNESDAY, June 23, 2021 (HealthDay News) -- Losing weight is hard, but many weight loss supplements promise to make the journey easy. Unfortunately, there's little high-quality research to back these claims, a new study shows.
Hundreds of weight loss supplements like green tea extract, chitosan, guar gum and conjugated linoleic acid are being hawked by aggressive marketers. And an estimated 34% of Americans who want to lose weight have tried one, according to the researchers.
"The temptation is great because someone has a megaphone, but you don't need a celebrity endorsement and/or splashy headlines to tell you how to lose weight. The medical establishment will speak loudly and clearly when there's something to say," said study co-author Dr. Srividya Kidambi, an associate professor and chief of endocrinology and molecular medicine at the Medical College of Wisconsin.
To find out if 14 weight loss supplements and/or alternative therapies like acupuncture do what they claim, researchers identified 315 randomized-controlled trials, which are considered the gold standard in clinical research. Of these, 52 studies were deemed unlikely to be biased. Just 16 studies showed differences in weight between participants receiving treatment and those in the placebo arm.
The weight loss in these studies ranged widely, from less than 1 pound to just under 11 pounds. Weight loss was not seen consistently for any one weight loss treatment, and many had conflicting results, with some studies showing weight loss and others showing no such effect.
The studies included in the review looked at chitosan, a complex sugar formed from the hard shells of shellfish; ephedra or