Diet, eating behaviour and weight gain in men and women with overweight/obesity receiving varenicline for smoking cessation.

Because trying to quit smoking and not gain weight requires changes in two major behaviours simultaneously we explored eating behaviour in smokers with overweight/obesity making a quit attempt using guideline-based treatment. Participants were randomized to a carbohydrate-reduced or fat-reduced diet. The Three Factor Eating Questionnaire and Binge Eating Scale were completed by 48 of 64 participants in the low-carbohydrate and 47 of 58 in the fat-reduced group at randomization, after 6 and 14 weeks. At 6 weeks, no between group differences were seen in eating behaviour scores thus, we combined the sample for further analyses. In the combined sample, restraint increased (3.94 [95% CI 3.05, 4.83]), disinhibition (uncontrolled eating) decreased (-0.86 [95% CI-1.31, -0.41]) and binge eating decreased (-1.95 [95% CI -2.83, -1.06]), while hunger scores did not change (-0.43 [95% CI -0.89, 0.03]) after 14 weeks. In a general linear model, increase in dietary restraint (P = .012) and decrease in binge eating (P = .040) were associated with lower weight gain (model R2 adj = .147). In a smoking cessation program, dietary support regardless of diet was associated with increased dietary restraint and reduced binge eating. Because smoking cessation causes weight gain these results indicate that dietary support leads to eating behaviour changes that may prevent weight gain.