One of the most widespread problems in the life of a teenager is obesity. 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 graph called Percentage of Overweight Teens between the ages of 12 and 19, over the years from 1980 to 2000 the number of obese teenagers in the United States tripled, from 5 to 15 percent. Adolescent obesity is caused by several factors. One of the dominant factors leading to adolescent obesity is lack of exercise. According to a letter to the editor of a school newspaper, physical activity decreased 13 percent from 1980 to 2000, while the number of obese adolescents increased. This shows the impact of exercise on a teenager's body. Teens should get at least 30 minutes of moderately intense exercise every day. As stated in “Adolescent Obesity,” physical activity is very important in both the prevention and treatment of obesity. It is mandatory to burn the calories acquired by eating food. Studies show that children and adolescents who ar...