From the Guidelines
There is no single "best" over-the-counter supplement for weight loss, as most have limited scientific evidence supporting their effectiveness. According to the most recent and highest quality study 1, despite widespread marketing and exorbitant claims, there is no clear evidence that nutrition supplements are effective for obesity management or weight loss. Several large systematic reviews show that most trials evaluating nutrition supplements for weight loss are of low quality and at high risk for bias. High-quality published studies show little or no weight loss benefits.
Some supplements, such as green tea extract, protein supplements, and fiber supplements, may have some benefits, but the evidence is limited and the results are minimal. For example, green tea extract may slightly increase metabolism and fat oxidation, but a typical dose of 250-500mg daily, standardized to contain 45-50% EGCG, is required 1. Protein supplements, like whey protein at 20-30g per serving, may help with weight management by increasing satiety and preserving muscle mass during calorie restriction. Fiber supplements, such as psyllium husk (3-5g before meals), can promote fullness.
However, for effective weight loss, focus on creating a calorie deficit through a balanced diet and regular physical activity. Many weight loss supplements make exaggerated claims and some may contain harmful ingredients or interact with medications. Always consult with a healthcare provider before starting any supplement, especially if you have existing health conditions or take medications. The most effective approach to weight loss is a comprehensive weight loss maintenance program that provides at least monthly contact with trained interventionists and focuses on ongoing monitoring of body weight, nutrition, and behavioral changes, as well as participation in high levels of physical activity (200–300 min/week) 1.
From the Research
Non-Prescription Supplements for Weight Loss
The search for effective non-prescription supplements for weight loss has led to the investigation of various compounds, including glucomannan.
What is Glucomannan?
- Glucomannan is a soluble, fermentable, and highly viscous dietary fiber derived from the root of the elephant yam or konjac plant.
- It is native to Asia and has been studied for its potential in promoting weight loss 2.
Efficacy of Glucomannan for Weight Loss
- Preliminary evidence suggests that glucomannan may promote weight loss, with studies showing significant weight loss in overweight and obese individuals at doses of 2-4 g per day 2.
- However, not all studies have found glucomannan to be effective for weight loss, with some trials showing no significant difference in weight loss between glucomannan and placebo groups 3, 4.
- A systematic review and meta-analysis of randomized clinical trials found that the evidence for the efficacy of glucomannan in body weight reduction was not statistically significant, although some individual studies did report significant weight loss 4.
Studies on Glucomannan and Weight Loss
- A 2003 study found that a stimulant-free dietary supplement containing glucomannan, chitosan, fenugreek, Gymnema sylvestre, and vitamin C resulted in significant body weight and fat loss in obese adults 5.
- An 1984 clinical study found that glucomannan fiber supplementation resulted in a significant mean weight loss of 5.5 lbs over an eight-week period, as well as reductions in serum cholesterol and low-density lipoprotein cholesterol 6.