It is well established that middle-aged and older smokers weigh less than comparably aged non-smokers. In a review of 29 cross-sectional studies evaluating weight and smoking status, smokers weighed an average of 3.4 kg less than non-smokers (1,20,21). Weight differences between smokers and non-smokers tended to be greater for moderate smokers (compared to light or heavy smokers), older smokers, and women (20). Although most studies have been conducted in American populations, similar weight differences between smokers and non-smokers (as well as a more pronounced weight-control effect for women compared to men) were reported from the World Health Organization MONICA project, which assessed weight and smoking status in 69 000 individuals from 42 populations (22).
This weight-attenuating effect of smoking, observed in adults after decades of smoking, is small or
non-existent in adolescent and young adult smokers. In a biracial sample of 6751 seventh grade students (average age of 13 years), daily smokers had a significantly higher body mass index (BMI) than non-smokers (21.61 vs. 20.56 kg/m2, respectively) (23). Among 1926 members of this sample who were followed prospectively for 4 years, those who began smoking had greater increases in body weight for 2 years after initiation of smoking compared to non-smokers, especially white females after one year of smoking, and black males after 2 years of smoking. For those youths who smoked three or more years, body weight was virtually identical compared to those who never smoked (24). In a cross-sectional study of more than 31 000 young adult military recruits, smoking had no relationship to body weight in females, and a very small effect of body weight reduction in males, averaging less than 1kg (25). Finally, Klesges et al. (26), in a 7-year prospective study of more than 4000 black and white young adults (18-30 years of age at baseline), reported that smoking produced a small attenuation of weight gain among Blacks (2.6 kg over 7 years, or 0.4 kg per year, adjusted for gender, baseline weight, age, education, physical fitness, alcohol intake, and fat intake). In contrast, smoking had no weight-attenuating effect among white men or women in this study, the latter being the group most likely to report smoking to control body weight (10). In summary, smokers weigh 3-4 kg less than non-smokers, on average, after many years of smoking. However, smoking has minimal impact on body weight in young smokers.
Was this article helpful?