Healthy eating habits can't begin early enough. For kids, the American Heart Association recommends a diet high in whole grains, vegetables and fruits — but with limited juice — and low in saturated fat, trans fat, salt and added sugars. Infants need extra fat and calories for development, but as they grow, they should begin to eat a leaner diet. "Until age 2, kids should be taking whole milk," says Hagan, "but beginning at age 2, they should be on a lower-fat milk. We want them to develop a taste for low fat."