Students’ summer learning loss, the loss of academic of skills and knowledge over summer break, has been well documented in recent years. New research shows that younger elementary students are also at risk for weight gain during the summer. This contradicts common perceptions that kids get more physical activity in the summer when they have more opportunities to be outside. With so much emphasis in recent years on school-based strategies to prevent and reduce childhood obesity, it is difficult to see new data that shows it may not be enough. The research tells us that school-based initiatives need to be complemented with summer programs that emphasize nutrition education and physical activity. We can’t let our guard down just because it is summer.