Comparative effects of nutraceuticals on body weight in adults with overweight or obesity: A systematic review and network meta-analysis of 111 randomized clinical trials

There is no research on the comparative effects of nutraceuticals on weight loss in adults with overweight or obesity. This study aimed at quantifying and ranking the effects of different nutraceuticals on weight loss. We searched PubMed, Scopus, and Web of Science to November 2022. We included randomized trials evaluating the comparative effects of two or more nutraceuticals, or compared a nutraceutical against a placebo for weight loss in adults with overweight or obesity. We conducted random-effects network meta-analysis with a Frequentist framework to estimate mean difference [MD] and 95% confidence interval [CI] of the effect of nutraceuticals on weight loss. One hundred and eleven RCTs with 6171 participants that investigated the effects of 18 nutraceuticals on body weight were eligible. There is moderate certainty of evidence that supplementation of spirulina (MD: -1.81 kg, 95% CI: -2.53, -1.10), and garlic (MD: -0.56 kg, 95%CI: -1.10, -0.0.01) can result in a small improvement in body weight. Supplementations with psyllium (MD: -3.70 kg), chitosan (MD: -1.70 kg), grape seed (MD: -1.79 kg), green tea (MD: -1.04 kg), curcumin (MD: -0.82 kg), and resveratrol (MD: -0.97 kg) demonstrated small weight loss, but the certainty of evidence was rated very low to low. Based on our findings, supplementations with nutraceuticals can result in a small weight loss in adults with overweight or obesity.