Vending-machine junk food, too few gym classes  -- schools make kids fat, right? Not so, says a new study in the American Journal of Public Health, which found that 5- to 7-year-olds gain weight twice as quickly during the lazy days of summer than the busy school year. Tips for battling the bulge, from the American Dietetic Association:

• Stick to the same meal and snack schedule as during the school year. Kids are less likely to eat constantly when they follow a regular routine.

• Keep a variety of low-fat, high-fiber treats around, like fresh fruit, to encourage kids to pick healthy foods.

• Get your child outside to play tag, climb trees  -- anything that gets him moving instead of vegging.

• Enroll him in a class or activity he likes to put some structure into the week. Even better: Find something fun you can do together.

---