"Since the early 1970s, the percentage of American children and adolescents defined as overweight has more than doubled, to about 15 percent, according to the Centers for Disease Control and Prevention. Three of four overweight teenagers remain overweight as adults and three hundred thousand people die each year due to obesity-related causes, making obesity the second, leading cause of death after smoking. Being overweight or obese increases the risk of hypertension, heart disease, stroke, diabetes and some cancers.