ABSTRACT: BACKGROUND:Both body mass index (BMI) and the perceived importance of health have received a lot of attention, but few studies have fully investigated the interaction of their effects on health behaviors. OBJECTIVE:This study investigates the effects of BMI and the perceived importance of health on health behaviors (patterns of eating, sleeping, and exercising) among college students in Taiwan. METHODS:A survey was conducted with 334 students to assess their perception of the importance of health (using indicators) and their health behavior (using the Health Behaviors Scale). Respondent BMI was calculated from self-reported body weight and height. Descriptive statistical analysis, independent t test analysis, two-way analysis of variance (ANOVA), and one-way ANOVA were conducted. RESULTS:The results showed a significant difference between genders in health behaviors among college students (eating: t332=2.17, P=.03; exercise: t332=5.57, P<.001; sleep: t332=2.58, P=.01). Moreover, there was an interaction between BMI and perception (of the importance of health) for exercise behaviors (F2,328=3.50, P=.03), but not for eating behaviors (F2,328=0.12, P=.89) or sleep behaviors (F2,328=1.64, P=.20). CONCLUSIONS:This study establishes, for the first time, the interaction of BMI and the perceived importance of health on health behaviors. The perception of health was found to have a significant effect on exercise behaviors. Thus, the perception of health plays a significant role in the exercise behaviors of college students in Taiwan. This finding provides researchers, policy makers, and practitioners with evidence, and consequently, opportunities for focusing on preventive actions. The findings suggest that increasing the importance of health in the perception of college students, should be the focus of efforts to help students exercise more regularly.