Obesity is one of the most common problems in a teenager's life. It affects between 5 and 30 percent of children in the United States, which means there could be approximately 12 million adolescents suffering from obesity in the United States today. According to a chart titled Percentage of Overweight Adolescents Ages 12 to 19, between 1980 and 2000, the number of obese adolescents in the United States tripled, from 5 to 15 percent. Obesity in adolescents is caused by several factors. One of the dominant factors that lead to obesity among adolescents is lack of exercise. According to a letter to the editor of a high school newspaper, physical activity declined 13 percent between 1980 and 2000, while the number of obese adolescents increased. This shows the impact of exercise on a teenager's body. Teenagers should get at least 30 minutes of moderate-intensity exercise every day. As noted in “Adolescent Obesity,” physical activity is very important in both the prevention and treatment of obesity. It is mandatory to burn the calories gained by eating food. Studies show that children and adolescents who are...