Study designs of evaluations included in the review
Double-blind, randomised controlled trials (RCTs) were eligible for inclusion. The duration of the included studies ranged from 6 to 14 weeks for those in the meta-analysis, and from 8 to 26 weeks for other studies.
Specific interventions included in the review
Studies that compared monopreparations of chromium picolinate with placebo were eligible for inclusion. Studies that used chromium picolinate as part of a multicomponent intervention were excluded. The included studies used chromium picolinate in daily doses ranging from 188 to 1,000 microg. Cointerventions included weight training, running and advice to maintain usual diet.
Participants included in the review
The inclusion criteria relating to the participants were not specified. The included studies were of volunteers, varsity wrestlers, athletes, students, healthy men, obese diabetic patients and obese patients. The body mass index per treatment group, where reported, ranged from 28.4 to 33.2.
Outcomes assessed in the review
Studies that assessed body weight were eligible for inclusion. The primary outcome in the review was the mean change in body weight compared with baseline. The review also assessed the change in lean body mass and percentage body fat, and adverse effects.
How were decisions on the relevance of primary studies made?
Two reviewers independently selected the studies for inclusion and resolved any disagreements through discussion.