A review of more than 300 cases reveals that taking nutritional supplements to lose weight does not obtain any verifiable effect.

Green tea extract.

Despite the vast availability of scientific evidence on supplements and miracle diets of various kinds, in Spain and the rest of Western countries they are followed spending billions a year on nutritional supplements with the goal of losing weight.

However, and as a new study confirms, it is wasted spending: there is a clear lack of evidence around dietary supplements and alternative therapies for lose weight, as confirmed by the work published in Obesity, the magazine of the American Obesity Association.

Today there are hundreds of weight loss supplements on the market: green tea extract, chitosan, guar gum, conjugated linoleic acid, and the like. It is estimated that, only in the United States, 34% of those who have tried to lose weight have wasted their money in these types of supplements.

In the current work, the researchers tried to find some kind of evidence regarding the consumption of these supplements. So they completed a comprehensive review of 315 clinical trials in which supplements and therapies were used to lose weight. But they did not find such evidence, but on the contrary: the supplement use did not result in weight loss between users.

As John Batsis, MD, professor in the Division of Geriatric Medicine at the University of North Carolina in the School of Medicine and in the Department of Nutrition at the UNC Gillings School of Global Public Health, these findings are so important to clinicians. and researchers as well as for the industry: it is a rigorous evaluation of this type of products is necessary.

Furthermore, Batsis explains, this evaluation should be collaborative, as the supplement industry and researchers work together to design high-quality clinical trials.

In search of the easy solution

The study authors also explain that weight loss supplement users have often tried to lose or maintain weight in the past without success. And, in addition, they also highlight the lack of efficacy of FDA-approved therapies, o la lack of access to healthcare professionals that provide good obesity treatments.

While it is true that the Office of Dietary Supplements at the United States National Institutes of Health has advanced the science of dietary supplements by evaluating the information available on them and supporting their research, members of the Obesity Association decided that it was important to evaluate non-FDA therapies as well, in order to find and provide the best scientific evidence.

Thus, for this study the researchers carried out a comprehensive systemic review on the efficacy of supplements and alternative therapies in the pursuit of weight loss, in patients 18 years of age or older. Searches were carried out in Pubmed, Cochrane Library, Web of Science, CINAHL and Embase.

Total 315 randomized controlled clinical trials were analyzed, peer-reviewed. They were classified 52 studies as low risk of bias and enough to support the effectiveness of these supplements. And, of these, 16 showed significant differences in terms of weight loss., objectifying losses of between 0.3 and 4.93 kg, within the same groups studied. Dietary supplements did not appear to have a determined effect on these losses.

Thus, with these data, the members of the Clinical Committee of the Obesity Society advise physicians to consider this lack of evidence regarding the potential of non-FDA approved dietary supplements and therapies, and that they weigh the option of recommending proven, validated and sufficiently evidenced therapies.

Finally, the same committee maintains that adequate resources must be provided for obesity management, and misleading statements are evident when marketing and trying to sell products that are not only ineffective, but can be harmful to some patients.