Effects of Weight Loss Surgery on Bone Health in Adolescents

The purpose of this study is to examine the impact of weight-loss surgery (Roux-en-Y gastric bypass or Vertical Sleeve Gastrectomy) on bone outcomes in girls and boys ages 13-21. This study will also examine a group of overweight boys and girls who are not scheduled or planned for surgery for comparison of these outcomes. Obese adults who undergo weight-loss surgery are at risk for bone loss and decreased bone strength. The investigators do not know the effects of such surgery on bone in teenagers and young adults. The purpose of this study is to find out how different types of weight loss surgery affect bone density and strength in teenagers and young adults and compare these results to obese teenagers and young adults who are not undergoing weight-loss surgery.