1. Teach by example.
A Prevention survey found that children whose parents keep in shape are much more likely to have healthy body weights themselves. "There's nothing worse than telling a child what he needs to do and not doing it yourself," says Elizabeth Ward, R.D., a Boston nutritional consultant and author of Healthy Foods, Healthy Kids (Adams Media, 2002). "Set a good example and get your nutritional house in order first."
2. Don't say "clean your plate."
Young children instinctively know how much food they need. That instinct can disappear, however, when parents serve kids overly large portions or push them to eat more. A study at Penn State University in University Park illustrated this: When three-year-olds were served a larger-than-normal serving of macaroni and cheese, they ate only until their hunger was satisfied; five-year-olds, on the other hand, chowed down to excess. Encourage kids to eat enough to satisfy their appetites and stop before they're truly full.