Curbing the epidemic of childhood and adolescent obesity requires impacting multiple behaviors. This article examines the interrelationships of physical activity, fruit and vegetable consumption, and limiting television time among elementary, middle, and high school students.Nationwide samples of students in grades 4 through 12 (n=4091) completed self-administered questionnaires assessing Transtheoretical Model constructs and behavioral indicators for physical activity, fruit and vegetable consumption, and limiting television time. Analyses were conducted to compare the prevalence of students at-risk for the target behaviors across the age groups and to examine the interrelationships of the target behavior risks.Across the three age groups, physical activity and fruit and vegetable consumption declined, while limiting TV time increased. In addition, high school students had the greater number of behavioral risks. Across all three samples, being at-risk for one behavior almost always significantly increased the odds of being at-risk for another behavior.The findings of this study provide further evidence for the need for early promotion of healthy lifestyle behaviors. The relationships among the target behaviors in three samples strongly support a multiple behavior approach for obesity prevention. Transtheoretical Model-based tailored interventions are currently being used to change multiple behaviors without overwhelming students.