Changes in food intake and activity after quitting smoking.

Quitting smoking often results in weight gain. The causes of the gain are not known. The present study evaluated changes in calories, total sugars, sucrose, fat, protein, and nonsugar carbohydrates as well as changes in activity levels after quitting smoking. Ninety-five subjects were randomly assigned to either early (Week 2) or late (Week 6) quit dates. Subjects were assessed on weight, food intake, activity levels, and smoking levels at baseline, at Weeks 4 and 8, and at Weeks 12 and 26 postquit. The results indicated significant increases in calories, sucrose, and fats 2 weeks after the quit date. Changes for total sugars were less consistent. Activity levels did not change significantly. Early caloric increases predicted weight gain at 26 weeks for abstinent women. No relation was found for abstinent men, but interpretation of this finding is weakened by a small subsample size. Abstinent subjects gained over 9 lb by 26 weeks postquit. Despite this gain, Week 26 results showed that caloric intake for abstinent women was approximately equal to that observed at baseline, whereas that for abstinent men had dropped significantly.