Lifestyle risk factors for overweight in Japanese male college students

Objective: To identify lifestyle and sociodemographic risk factors of overweight among male college students. Design: A retrospective cohort study. Setting: Annual health checkup in a single university in Japan. Participants: Male students who underwent two successive health checkups from their third school year between 2000 and 2007 and whose BMI at baseline of this study was 22.0kg/m(2) or more (n 4634). Results: During the 1-year follow-up, 598 students (12.9%) reached the study endpoint, i.e. more than a 5% increase in BMI. Independent risk factors for substantial BMI increase included infrequent exercise (OR = 1.33; 95% CI 1.11, 1.60), no or infrequent alcohol drinking (OR = 1.30; 95% CI 1. 08, 1.57), frequently skipping breakfast (OR = 1.34; 95% CI 1.12, 1.61), preference for fatty food (OR 1.36; 95% CI 1.04, 1? 78) and living alone (OR 1.23; 95% CI 0.99, 1.52). Students were readily stratified according to risk for substantial BMI gain by counting the number of their risk factors. OR (95% CI) for the risk between the no risk factor group and students with two, three, four and five risk factors were 1.61 (0.96, 2.70), 2.24 (1.34, 33.75), 2.42 (1.39, 4.23) and 6.22 (2.58, 15.0), respectively. Conclusion: These data suggest that avoidance of certain risk factors in college life is associated with a decrease in incidence of overweight among male students.