Guar gum for body weight reduction: meta-analysis of randomized trials.

PURPOSE To determine the efficacy of the dietary fiber guar gum as a therapeutic option for reducing body weight by conducting a meta-analysis of randomized controlled trials. METHODS Literature searches were performed on the electronic databases Medline, Embase, Biosis, Amed, and the Cochrane Library. Manufacturers of commercial guar gum preparations and experts on the subject were contacted to provide any published or unpublished trials. For inclusion, trials had to state that they were randomized, double blinded, and placebo controlled, used guar gum monopreparations, and reported body weight as an endpoint. No language restrictions were imposed. Two reviewers independently extracted data in a standardized manner according to predefined criteria and evaluated methodological quality using the scoring system developed by Jadad. Discrepancies were settled through discussion. RESULTS Thirty-four trials were identified and 20 could be included. Eleven trials provided data that were suitable for statistical pooling. The meta-analysis indicated a nonsignificant difference in patients receiving guar gum compared with patients receiving placebo (weighted mean difference -0.04 kg; 95% confidence interval (CI): -2.2 to 2.1). Analysis of six trials with similar methodologic features corroborates these findings (weighted mean difference -0.3 kg; 95% CI: -4.0 to 3.5). Adverse events most frequently reported were abdominal pain, flatulence, diarrhea, and cramps. Overall, 11 patients (3%) dropped out owing to adverse events. CONCLUSIONS This meta-analysis suggests that guar gum is not efficacious for reducing body weight. Considering the adverse events associated with its use, the risks of taking guar gum outweigh its benefits for this indication. Therefore, guar gum cannot be recommended as a treatment for lowering body weight.