AIM: To explore the relationship between smoking and dieting in a cross-sectional nationally representative sample of young adolescents. METHODS: Smoking was assessed by serum cotinine concentrations in 1132 adolescents aged 12-18 y enrolled in the NHANES III study. Information on adolescents' weight loss attempts were obtained by questionnaire. Normal weight was defined as a body mass index (BMI) less than the 85th percentile for age and gender. Overweight was defined as a BMI equal to or greater than the 85th percentile for age and gender. Nutritional intake was assessed with a 24 h recall and food frequency questionnaire. RESULTS: There was a two-fold increase in smoking among normal-weight adolescent girls who reported trying to lose weight (23.7% vs 12.6%, P<0.01). In contrast, prevalence of smoking was similar among overweight adolescent girls who tried to lose weight compared to those who did not (15.8% vs 14.1%, P=0.76). Similar trends were observed in boys. However, overweight boys who were trying to lose weight were less likely to smoke than overweight boys who were not trying to lose weight (9.8% vs 24.5%, P<0.05). There were no differences in body weight, BMI, caloric intake or fat intake among smokers and non-smokers. However, smokers reported eating less fruit and vegetables compared to non-smokers, and were over five times more likely to drink alcohol compared to non-smokers (odds ratio:  1´/month, 5.28 (3.82-7.28), 4´/month, 5.29 (3.58-7.82). CONCLUSION: Tobacco use is common among normal weight adolescents trying to lose weight. Tobacco use is also associated with a cluster of other unhealthy dietary practices in adolescents. International Journal of Obesity (2001) 25, 1381-1385 | 
