The Effect of Weight Loss on Bone in Men

Inclusion Criteria: * Obese or overweight * Must live in the geographic vicinity of Rutgers University Exclusion Criteria: * Currently on any medication known to influence calcium or bone metabolism, including HRT, or with evidence of diseases known to influence calcium metabolism (i.e. metabolic bone disease, hyperparathyroidism, untreated thyroid disease, significant immune, hepatic, or renal disease, significant cardiac disease \[i.e., heart attack or stroke in the past 6 months., abnormal EKG\], active malignancy or cancer therapy within the past year) * History of kidney stones * Weight gain or weight loss (5% of body wt) within 3 months prior to recruitment * Participation in other investigational studies during the 12-month study period * Usually have a very high or low intake of calcium (more than 1500 or less than 500 mg per day)