Interventions for preventing weight gain after smoking cessation

Background Most people who stop smoking gain weight. There are some interventions that have been designed to reduce weight gain when stopping smoking. Some smoking cessation interventions may also limit weight gain although their effect on weight has not been reviewed. Objectives To systematically review the effect of: (1) Interventions targeting post‐cessation weight gain on weight change and smoking cessation. (2) Interventions designed to aid smoking cessation that may also plausibly affect weight on post‐cessation weight change. Search methods Part 1 ‐ We searched the Cochrane Tobacco Addiction Group's Specialized Register and CENTRAL in September 2011. Part 2 ‐ In addition we searched the included studies in the following "parent" Cochrane reviews: nicotine replacement therapy (NRT), antidepressants, nicotine receptor partial agonists, cannabinoid type 1 receptor antagonists and exercise interventions for smoking cessation published in Issue 9, 2011 of the Cochrane Library. Selection criteria Part 1 ‐ We included trials of interventions that were targeted at post‐cessation weight gain and had measured weight at any follow up point and/or smoking cessation six or more months after quit day. Part 2 ‐ We included trials that had been included in the selected parent Cochrane reviews if they had reported weight gain at any time point. Data collection and analysis We extracted data on baseline characteristics of the study population, intervention, outcome and study quality. Change in weight was expressed as difference in weight change from baseline to follow up between trial arms and was reported in abstinent smokers only. Abstinence from smoking was expressed as a risk ratio (RR). We used the most rigorous definition of abstinence available in each trial. Where appropriate, we performed meta‐analysis using the inverse variance method for weight and Mantel‐Haenszel method for smoking using a fixed‐effect model. Main results Part 1: Some pharmacological interventions tested for limiting post cessation weight gain (PCWG) resulted in a significant reduction in WG at the end of treatment (dexfenfluramine (Mean difference (MD) ‐2.50 kg, 95% confidence interval (CI) ‐2.98 to ‐2.02, 1 study), phenylpropanolamine (MD ‐0.50 kg, 95% CI ‐0.80 to ‐0.20, N=3), naltrexone (MD ‐0.78 kg, 95% CI ‐1.52 to ‐0.05, N=2). There was no evidence that treatment reduced weight at 6 or 12 months (m). No pharmacological intervention significantly affected smoking cessation rates. Weig