Review finds no 'high-quality' evidence that weight loss supplements work

Researchers conducted a systematic review of randomized controlled trials of a selection of weight loss supplements and alternative therapies.
They found no high-quality evidence of the efficacy of any of the products reviewed.
An accompanying opinion piece calls for closer scrutiny of the supplement industry and its role in promoting “misleading claims” about products.
The Council for Responsible Nutrition, which represents the supplement industry, has questioned the validity of this latest research.

Among adults in the United States trying to maintain a moderate weight, roughly a thirdTrusted Source say they have used dietary supplements to achieve their goal.

But, according to a new review, high-quality evidence of the benefits of many weight loss products and alternative therapies is currently lacking.

The systematic review of randomized controlled clinical trials — the gold standard of clinical research — appears in the journal ObesityTrusted Source.

“Our findings are important for clinicians, researchers, and industry alike, as they suggest the need for rigorous evaluation of products for weight loss,” says corresponding author John Batsis, M.D., of the University of North Carolina School of Medicine, Chapel Hill.

“Only then can we produce data that allows clinicians to provide input and advice with a higher degree of certainty to our patients,” he adds.

Lack of access to approved therapies

The prevalence of obesityTrusted Source among adults in the U.S. has continued to increase in recent years, from 33.7% in 2007–2008 to 39.6% in 2015–2016.

The condition also has associations with an increased risk of diabetes, heart disease, cancer, and premature death.

People often struggle to lose weight; due to either a lack of effectiveness of Food and Drug Administration (FDA)-approved treatments or no access to healthcare professionals who can provide anti-obesity therapy.

The researchers write that many people turn to nonprescription weight loss supplements in the belief that they are “natural” or “clinically proven.” Consumers may even believe these products are as safe as FDA-approved drugs.

In addition, the scientists say that healthcare professionals have incomplete information about the scientific claims made by the promoters of such therapies.

Products and therapies reviewed

The researchers reviewed randomized controlled trials that evaluated the efficacy of 14 dietary supplements, therapies, or both, including:

acupuncture
green tea
ephedra or caffeine
guar gum
chitosan
calcium-vitamin D supplements
chocolate or cocoa
chromium
pyruvate
mind-body therapies

Out of a total of 315 trials, they judged 52 to have a low risk of biasTrusted Source — due to flaws in their design or reporting of results, for example — and sufficient data to support any claims of efficacy.

Of these, 16 reported statistically significant weight reduction throughout the trial, ranging from 0.3 to 4.93 kilograms.

However, the authors write that these reductions were not “clinically significant.”

“An outcome can be statistically significant without being clinically significant,” Prof. Batsis told Medical News Today.

He said clinical guidelines consider a weight loss of more than 5% to be clinically significant.

“During our review of supplement studies, in the rare cases where people did lose weight, they did not drop enough pounds to make a positive impact on their health,” he said.

Review finds no ‘high-quality’ evidence that weight loss supplements work

Researchers conducted a systematic review of randomized controlled trials of a selection of weight loss supplements and alternative therapies.

They found no high-quality evidence of the efficacy of any of the products reviewed.

An accompanying opinion piece calls for closer scrutiny of the supplement industry and its role in promoting “misleading claims” about products.

The Council for Responsible Nutrition, which represents the supplement industry, has questioned the validity of this latest research.

Among adults in the United States trying to maintain a moderate weight, roughly a thirdTrusted Source say they have used dietary supplements to achieve their goal.

But, according to a new review, high-quality evidence of the benefits of many weight loss products and alternative therapies is currently lacking.

The systematic review of randomized controlled clinical trials — the gold standard of clinical research — appears in the journal ObesityTrusted Source.

“Our findings are important for clinicians, researchers, and industry alike, as they suggest the need for rigorous evaluation of products for weight loss,” says corresponding author John Batsis, M.D., of the University of North Carolina School of Medicine, Chapel Hill.

“Only then can we produce data that allows clinicians to provide input and advice with a higher degree of certainty to our patients,” he adds.

Lack of access to approved therapies

Products and therapies reviewed

The researchers reviewed randomized controlled trials that evaluated the efficacy of 14 dietary supplements, therapies, or both, including:

acupuncture

green tea

ephedra or caffeine

guar gum

chitosan

calcium-vitamin D supplements

chocolate or cocoa

chromium

pyruvate

mind-body therapies

Out of a total of 315 trials, they judged 52 to have a low risk of biasTrusted Source — due to flaws in their design or reporting of results, for example — and sufficient data to support any claims of efficacy.

Of these, 16 reported statistically significant weight reduction throughout the trial, ranging from 0.3 to 4.93 kilograms.

However, the authors write that these reductions were not “clinically significant.”

“An outcome can be statistically significant without being clinically significant,” Prof. Batsis told Medical News Today.

He said clinical guidelines consider a weight loss of more than 5% to be clinically significant.

“During our review of supplement studies, in the rare cases where people did lose weight, they did not drop enough pounds to make a positive impact on their health,” he said.

Related

Related posts

Leave a Comment Cancel Reply