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

PURPOSE: To determine the efficacy of the dietary fiber guar gum as a thera peutic option for reducing body weight by conducting a meta-analysis of ran domized controlled trials. METHODS: Literature searches were performed on the electronic databases Med line, Embase, Biosis, Amed, and the Cochrane Library. Manufacturers of comm ercial guar gum preparations and experts on the subject were contacted to p rovide any published or unpublished trials. For inclusion, trials had to st ate that they were randomized, double blinded, and placebo controlled, used guar gum monopreparations, and reported body weight as an endpoint. No lan guage restrictions were imposed. Two reviewers independently extracted data in a standardized manner according to predefined criteria and evaluated me thodological quality using the scoring system developed by Jadad. Discrepan cies were settled through discussion. RESULTS: Thirty-four trials were identified and 20 could be included. Eleve n 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 -0.0 4 kg; 95% confidence interval (CI): -2.2 to 2.1). Analysis of six trials wi th similar methodologic features corroborates the se findings (weighted mea n 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 f or reducing body weight. Considering the adverse events associated with its use, the risks of taking guar gum outweigh its benefits for this indicatio n. Therefore, guar gum cannot be recommended as a treatment for lowering bo dy weight. Am J Med. 2001;110:724-730. (C) 2001 by Excerpta Medica, Inc.