Experts Question the Effectiveness of Weight-Loss Supplements
Key Takeaways:
- Most weight-loss supplements, including popular ones such as garcinia cambogia, green tea extract, and conjugated linoleic acid, do not lead to significant weight loss, based on recent comprehensive analyses and clinical studies.
- Weight-loss supplements are a substantial global business, grossing $41 billion, but can pose health risks and economic strains due to limited regulations around their safety and efficacy.
- White kidney bean (Phaseolus vulgaris) was the only supplement evaluated to result in statistically significant weight loss compared to a placebo, but the weight loss was minor and unlikely to provide significant health benefits.
- Potential risks of these supplements include severe gastrointestinal symptoms (in case of high doses of fructooligosaccharides) and potential reactions with other medications. Consumers should approach these products with caution, as they are not regulated by the FDA until complaints are received.
- Decisions regarding the use of supplements should be made case-by-case, and people should understand that being marketed does not equate to safety or FDA approval.
It appears that common weight-loss supplements such as garcinia cambogia, green tea extract, glucomannan, conjugated linoleic acid, and chitosan do not offer any substantial benefit, according to recent comprehensive analyses.
The majority of clinical studies investigated indicated these supplements did not lead to notable weight loss among users, and in the few instances where weight was reduced, the amount lost was not substantial enough to positively affect health.
Findings from Systematic Review
“Our systematic review findings underscore this fact: relying on herbal medicines or dietary supplements is not an effective weight-loss strategy,” quotes chief investigator Erica Bessell, working towards her doctorate at the University of Sydney, Australia. She suggests individuals looking to shed weight should save their funds and opt for evidence-based treatment.
The first exhaustive analysis in 16 years of weight-loss supplements encompassed the outcomes of 121 clinical trials comprising nearly 10,000 participants. Their results were presented at a virtual annual gathering of the European Congress of Obesity and published in the International Journal of Obesity and the Diabetes, Obesity & Metabolism journal.
The Weight-loss Supplement Business and Risks
Weight-loss supplements grossed $41 billion globally, according to background data shared by the researchers. A vast array of these products is marketed in the United States, with approximately 15% of Americans looking to lose weight having tried one.
Dr. Scott Kahan, director of the National Center for Weight and Wellness, in Washington, D.C, noted that these supplements are not only expensive but can also pose health risks given the limited regulations surrounding dietary supplements.
Effectiveness of Different Supplements
Of all the supplements evaluated, only white kidney bean (Phaseolus vulgaris) resulted in statistically significant weight loss compared to placebo, However, those using it only reduced their weight by around 3.5 lbs, an insignificant amount concerning health advantages.
Supplements without scientifically established benefits include:
- Tropical fruit extracts like garcinia cambogia, mangosteen, and African mango
- Green tea extract
- Plant-based substances like yerba mate, veld grape, licorice root, and East Indian Globe Thistle
- Chitosan, a complex sugar formed from shellfish hard shells
- Glucomannan, a soluble fiber sourced from the roots of the elephant yam
- Fructans, carbohydrates found in fruits and vegetables
- Conjugated linoleic acid (CLA), a natural substance produced in the gut by the digestion of fats
“Very few of these supplements were found to cause clinically relevant weight loss,” Bessell said, adding that many of these trials were likely to be biased, and the design and conduct of the trials were often inadequately reported. As such, there is currently no strong evidence to recommend any of these supplements for weight loss.”
Potential Risks and Safety Concerns
Even though most of the supplements seemed safe for short-term use, they did come with risks, the most immediate one being a strain on your wallet. In 2004, the U.S. Food and Drug Administration banned the sale of ephedra, a weight-loss supplement, due to grave safety risks that included heart attack, seizure, stroke, and sudden death.
Another supplement that poses safety challenges is fructooligosaccharides, which at high doses have been known to cause severe gastrointestinal symptoms.
Dietary supplements are not regulated by the FDA, only stepping in when complaints from consumers are received. The situation raises concerns about the actual content of the supplements compared to what’s listed on the label.
Also, there is a potential that a supplement might react to one of the prescriptions you’re taking, Bessell added.
Kahan emphasized, “consumers need to be aware this is a situation of caveat emptor. People often believe inappropriately that if it’s being marketed that it’s safe, that the FDA has approved it or signed off on it, and that’s not the case in terms of dietary supplements.”
Bessell stated, “Any product can be marketed, and the FDA can only remove products from the market if there is evidence that the product is unsafe or if the product label is misleading in terms of listed ingredients or claims of benefit.”
Based on this new study, consumers should make decisions on supplements on a case-by-case basis, according to Andrea Wong, Ph.D., senior vice president of scientific and regulatory affairs at the Council for Responsible Nutrition.
More Information
The U.S. Food and Drug Administration has more about dietary supplements.
SOURCES: Erica Bessell, dietitian and doctoral student, University of Sydney, Australia; Scott Kahan, MD, MPH, director, National Center for Weight and Wellness, Washington, D.C.; Andrea Wong, Ph.D., senior vice president of scientific and regulatory affairs, Council for Responsible Nutrition; European Congress on Obesity, virtual presentation, May 7, 2021
