The rate of childhood obesity has more than tripled during the past 30 years. Research shows that preventionat an early age is more effective than treatment later in life. Energize is a multicomponent intervention incorporated into theschool day that combines nutrition education and physical activity aimed at maintaining healthy weight among elementaryschool youth. This study evaluated the effectiveness of the Energize program for changing dietary and physical activity habitscompared to a control group of children not participating in the program.