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This project was designed to determine the extent to which weight gain and changes in fat distribution after smoking cessation predict the rate of relapse during a one-year follow-up period. The study was conducted in male and female smoking cessation class participants. Key variables were assessed 1-week before cessation, at cessation, and then at weeks 1, 2, and 4, and months 3, 6, 9, and 12 after cessation. These included smoking status; perceived and actual weight; and waist, thigh, and hip circumferences. Individual difference variables (e.g., gender, age, smoking history, weight gain history) were assessed at baseline to determine their ability to identify subjects most prone to weight gain and to weight-related relapse. The specific aims of this project were to: (1) determine the magnitude of change in actual and perceived weight, fat distribution, and smoking status during the 1-Year follow-up period separately for men and women; (2) determine the extent to which changes in actual and perceived weight and fat distribution predict the rate of relapse separately for men and women; and (3) investigate the degree to which hypothesized moderating variables (e.g., gender, age, smoking history, weight gain history, negative reactions to weight gain, previous difficulty with losing weight, attributing previous relapse to weight gain) identify which subjects are most prone to weight gain and to weight-related relapse. Baseline examinations were completed on 325 participants, of which 267 completed the 1-year follow-up. Analyses examined weight change in the 67 subjects who remained abstinent for the first year after smoking cessation compared to 47 nonsmokers assessed on a similar schedule. On average, the successful quitters gained 0.9 pounds at 1 week, 1.9 pounds at 1 month, 3.6 pounds at 3 months, 4.9 pounds at 6 months, and 5.6 pounds at 12 months. Weight gains at all but the first week were significantly (p<.0001) greater in quitters than nonsmokers. Analyses examined the correlates of weight change in these quitters. Measures of nicotine intake/dependence were not correlated with the amount of weight gain at 12 months. There was a trend for younger quitters and for quitters with higher body mass index to gain more (r2 = 0.23 and 0.22, respectively, both p < IO), but no differences between males and females emerged. The amount of weight gain at 1 week and 1 month were predictive of the amount of weight gain at 1 year (r2 = 0.52 and 0.55, respectively, both p<.0001). Pilot testing was completed in 20 volunteers who had bioelectrical impedance measures taken before smoking cessation and weekly for 1 month after. Analyses indicated that total body water correlated significantly with change in weight and that most of the weight gain experienced in the first month after cessation is explainable by increases in body water. |
