Involving the whole family lifts a psychological burden off your child. “Then eating better foods isn’t a punishment, but a new way of life,” says Elyse Tyler, a registered and licensed pediatric dietitian at Children’s Medical Center Dallas. It’s vital to balance the energy, or calories, that you take in and the calories that you burn. “The body is like a bank,” Tyler says. “You make deposits when you eat and withdrawals when you move.”

• Be a role model. “If you set a good example, they will follow,” says Tyler. “If you’re not doing it for yourself, do it for your children.”
• Set firm rules. Learn how to say no to your kids and how to set and enforce boundaries.
• Set specific, reachable goals. Limit TV time, for instance, or request a certain level of physical activity in a given period.
• Praise and reward children. Compliment them for eating healthier snacks, or celebrate milestones with a CD. Never use food as a reward or withhold it as punishment.
• Expect slips. “If a kid lapses once a week by eating a slice of pizza or an ice cream cone, that’s fine,” says Tyler. But three times a week is a relapse — and you and your child need to talk.