The Effect of Weight Loss on Bone in Men

This pilot study of the effect of weight loss on bone health in men is being undertaken in conjunction with studies of the effect of weight loss on bone health in women for comparison purposes. See NCT00473031, NCT00472680, and NCT00472654. This information is important for determining optimal nutrient requirements during weight loss.

Participants will be recruited for both weight loss and weight maintenance. All participants will be asked to take a daily vitamin/mineral supplement and, depending on their usual food intake, they may be asked to take a calcium tablet to meet the recommended intake throughout the study period. Weight loss participants will attend regular counseling sessions (about 45 minutes each) with a dietitian for approximately 6 months; they will be asked to attend 6 sessions but will be given the opportunity to attend 13 sessions. Body composition will be measured by a dual-energy x-ray absorptiometry (DXA) machine, ultrasound, and peripheral quantitative computer tomography (pQCT) before and after 6 months of weight loss. Bone, mineral, protein and lipid markers, and hormones that influence bones will also be measured.

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)