Lead by example. Provide a consistent example of good nutrition by preparing foods rich in antioxidants, minerals, vitamins, and fiber. Incorporate fruits, vegetables and whole grains into every meal and snack.

Eat healthily as a family. Collectively choose to eliminate saturated fats, cholesterol, trans fats and high fructose corn syrup from 90% of all meals. Make a list of alternative food and snack options. Ask your teen to suggest his or her favorite fruits, nuts or low-fat dairy...