The Portion-Size Solution: Serve yourself smaller portions, and don't require kids to clean their plates.
Whether we admit it or not, most of us finish the majority of the food we put on our plates, regardless of how full we feel when the meal is done. "On average, every adult belongs to the clean-plate club, male or female," says Wansink. "We eat 92 percent of what we serve ourselves." If you are in the habit of serving yourself heaping helpings when you're at home or if you eat out at restaurants that routinely serve big portions just to get you in the door, you're likely eating way more than you need.
Kids, on the other hand, only eat an average of 56 percent of what they serve themselves, Wansink says, "partly because they don't know when they'll be full and partly because they don't know what they like. A lot of what they put on their plate is the amount of food they want to experiment with. Instead of insisting they clean their plates, just say, 'Well, if they eat half, then they’re normal!' Food is no longer a battleground." To instill a healthy relationship with food, Wansink recommends letting kids serve themselves (when they choose a food or the amount of a food, they're more likely to eat it) and making it perfectly acceptable for them to finish their meal without cleaning their plates.