0, p = .9962, occasional smokers, ��2(1) = 2.4, p = .1196, and late starters, ��2(1) = 2.0, p = .1608. Quitters/decreasers were as likely to be obese as late starters, ��2(1) = 1.2, p = .2772, and occasional smokers, ��2(1) = 1.4, p = .2301. The interaction than analyses (full results not presented) showed that there were no significant gender differences in the associations between smoking group memberships and obesity (data available upon request). As shown in Table 2, when the dependent variable was an indicator variable of being overweight or obese (BMI > 24.9), compared with nonsmokers, heavy continuous smokers and late starters had significantly lower likelihood (AOR = 0.39 and 0.47, respectively).
The likelihood ratio tests also showed that heavy continuous smokers and late starters had significantly lower likelihood of being overweight or obese than occasional smokers, ��2(1) = 10.7, p = .0011 and ��2(1) = 7.9, p = .0050, respectively. Discussion We investigated the association between trajectories of tobacco use from adolescence to young adulthood and adult obesity in the mid-30s. The findings provided partial support for our hypotheses. Compared with nonsmokers, heavy/continuous smokers or late starters had a significantly lower likelihood of obesity. Also, compared with nonsmokers or occasional smokers, heavy/continuous smokers or late starters had a significantly lower likelihood of being overweight or obese. Our findings that the heavy/continuous smokers or late starters are less likely to be obese than nonsmokers or occasional smokers are partially consistent with the findings of a number of investigators who have conducted cross-sectional or longitudinal studies.
For example, several investigators have noted that smokers in comparison with nonsmokers are less obese (Molarius, Seidell, Kuulasmaa, Dobson, & Sans, 1997). Even though smokers are less likely to be obese than nonsmokers, they do have higher morbidity and mortality compared with nonsmokers (CDC, 2005; Ezzati & Lopez, 2003). Of great interest are the possible mechanisms that intervene between smoking and less obesity. First, smokers, particularly the late starters, may use smoking as a strategy for weight control. This may occur more frequently among adolescents and young adults. Second, nicotine does suppress one��s appetite, and a decrease in appetite ultimately leads to lower caloric intake and lower body weight (Williamson, 1993).
AV-951 Third, tobacco use has an effect on the expenditure of energy (Perkins, 1992; Kvaavik et al., 2004). Smoking appears to lower the efficiency of caloric storage and to increase the metabolic rate, each of which may lead to lower body weight. For example, Perkins reported that up to 30 min after smoking, energy expenditure is approximately 10% higher than the normal energy expenditure. As noted by Kvaavik et al.