not just morbidly obese but actually two categories higher than that. >> dr. nadler says 25% of all high school age children are either overweight or obese, and he believes that those most obese face health risks such as high blood pressure, diabetes, and depression, that far outweigh the risks of any weight loss surgery. but some disagree. like dr. edward livingston who turns away most young patients. >> kids don't really know what they're getting into. i think you have to be really careful with children. >> before surgery, maria had to meet with a nutritionist, pediatric cardiologist and psychologists for approval. >> my name is maria. >> she also wrote this letter to her insurance company seeking coverage. you told the insurance company you need this surgery to make it to your 15th birthday. >> doctors have told me for years that if i keep gaining weight, i'm not going to see 18. and that has terrified me. i want to live. i want to do so many things.