CONTEXT: A Healthy People 2020 objective is to increase the prevalence of healthy-weight adults in the U.S. A systematic review of the effectiveness and safety of strategies to prevent weight gain in adults was performed.
EVIDENCE ACQUISITION: MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, CINAHL, PsycINFO, and ClinicalTrials.gov were searched through June 2012. Two reviewers independently reviewed titles, abstracts, and articles. Trials and observational studies with at least 1 year of follow-up that reported on strategies to prevent weight gain or maintain weight were included. Data were abstracted on weight, adherence, safety, and quality-of-life outcomes. The quantity, quality, and consistency of the evidence were graded, with a focus on studies' risks of bias, consistency of results across studies, how directly the question of interest was addressed, and precision of results. A meaningful difference and a significant threshold (p<0.05) were used to identify effective strategies. Evidence was synthesized qualitatively.
EVIDENCE SYNTHESIS: Twenty-two studies (11 trials and 11 observational studies) involving 480,142 participants were included. The strength of evidence is low for all strategies, but effective approaches may include low-fat diets, eating fewer meals prepared away from home, eating more fruits and vegetables, monitoring heart rate during exercise, and participation in group lifestyle sessions with reminder text messages. Safety and quality of life were rarely reported.
CONCLUSIONS: Although the evidence is not strong, there may be effective strategies to prevent weight gain.