Bone loss may occur after bariatric (weight loss) surgery, but standard methods of measuring bone density in obese patients are potentially inaccurate. This study uses quantitative computed tomography to examine changes in bone mineral density after bariatric surgery. We are also studying mechanisms which may explain bone loss after bariatric surgery.

Inclusion Criteria:

• Either scheduled for Roux-en-Y Gastric Bypass surgery or enrolled in a lifestyle weight management program

Exclusion Criteria:

• Weight ≥ than 450 lbs
• Postmenopausal women
• Significant heart, kidney, liver, or malignant disease
• Current disorders known to affect bone
• Use of medications known to affect bone for more than 7 days in the past 12 months

Obese adults