In the past 30 years, the prevalence of obesity in children has increased to epidemic proportions. The obesity rate among children ages 2 to 5 has more than doubled (from 5 percent to 10.4 percent); more than quadrupled (from 4.2 to 17 percent) among children ages 6 to 11; and more than tripled among adolescents ages 12 to 19 (from 4.6 to 17.6 percent). Today, nearly one-third of American children and adolescents (more than 23 million) are overweight or obese, placing them at a heightened risk for hypertension, high cholesterol, sleep apnea, orthopedic problems, and type 2 diabetes. If the obesity epidemic continues unabated, today's generation of American children may be the first to live sicker and die younger than their parents' generation. Preventing obesity during childhood is critical, because habits that last into adulthood frequently are formed during youth. Every school district must develop and implement a local school wellness policy as mandated by provisions of the 2004 Child Nutrition and WIC Reauthorization. When properly implemented, comprehensive wellness plans can help schools become models of healthy environments for children to learn and grow. By focusing on healthy, nutritional eating practices and physical activities schools can seize the opportunity to educate children about the life-long importance of nutrition and physical well-being. (Contains 19 endnotes.)