A Systematic Review of Dietary Supplements and Alternative Therapies for Weight Loss

 John A. Batsis, John W. Apolzan, Pamela J. Bagley, Heather B. Blunt, Vidita Divan, Sonia Gill, Angela Golden, Shalini Gundumraj, Steven B. Heymsfield, Scott Kahan, Katherine Kopatsis … See all authors 

First published: 23 June 2021

 

https://doi.org/10.1002/oby.23110

Citations: 1

Work was conducted in part at Dartmouth-Hitchcock, the Geisel School of Medicine at Dartmouth, and The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, New Hampshire, USA.

PDF: https://onlinelibrary.wiley.com/doi/epdf/10.1002/oby.23110

Abstract

Objective

Dietary supplements and alternative therapies are commercialized as a panacea for obesity/weight gain as a result of the minimal regulatory requirements in demonstrating efficacy. These products may indirectly undermine the value of guideline-driven obesity treatments. Included in this study is a systematic review of the literature of purported dietary supplements and alternative therapies for weight loss.

Methods

A systematic review was conducted to evaluate the efficacy of dietary supplements and alternative therapies for weight loss in participants aged ≥18 years. Searches of Medline (PubMed), Cochrane Library, Web of Science, CINAHL, and Embase (Ovid) were conducted. Risk of bias and results were summarized qualitatively.

Results

Of the 20,504 citations retrieved in the database search, 1,743 full-text articles were reviewed, 315 of which were randomized controlled trials evaluating the efficacy of 14 purported dietary supplements, therapies, or a combination thereof. Risk of bias and sufficiency of data varied widely. Few studies (n = 52 [16.5%]) were classified as low risk and sufficient to support efficacy. Of these, only 16 (31%) noted significant pre/post intergroup differences in weight (range: 0.3-4.93 kg).

Conclusions

Dietary supplements and alternative therapies for weight loss have a limited high-quality evidence base of efficacy. Practitioners and patients should be aware of the scientific evidence of claims before recommending use.

Study Importance

What is already known?

• ►Dietary supplements and alternative therapies for weight loss are widely available and used for the treatment of obesity.
• ►Deregulation of the dietary supplement industry permits marketing of such products without stringent regulatory approval.
• ►Use of dietary supplements and alternative therapies among adults with obesity is high despite their limited evidence base.

What does this study add?

• ►There is weak evidence for the efficacy of dietary supplements and alternative therapies.
• ►The number of randomized controlled trials varies, depending on the therapy examined.
• ►Design of existing trials is hampered by a significant risk of bias due to methodological inconsistencies.

How might these results change the direction of research?

• ►There is a critical need to strengthen the industry-academic relationship to design high-quality trials in this sphere.
• ►Emphasis on clearer outcomes, enhanced methodological rigor, and study duration are needed.
• ►The interaction between existing lifestyle interventions and existing supplements should be evaluated in future trials.

https://onlinelibrary.wiley.com/doi/10.1002/oby.23110