Moderate weight loss in obese and overweight men preserves bone quality.

BACKGROUND

Weight loss (WL) negatively affects bone mineral density (BMD) in older populations and has specifically been shown in women.

OBJECTIVE

In this prospective controlled trial, we examined variables of bone quality and endocrine changes after intentional WL in men.

DESIGN

Thirty-eight overweight and obese [mean ± SD body mass index (in kg/m²): 31.9 ± 4.4; age: 58 ± 6 y] men were recruited to either WL through caloric restriction or weight maintenance (WM) for 6 mo.

RESULTS

There was a -7.9 ± 4.4% and +0.2 ± 1.6% change in body weight in the WL and WM groups, respectively. There was a greater increase in femoral neck and total body BMD and bone mineral content (BMC) in the WM group than in the WL group (P-interaction effect < 0.05). In contrast, there was a trend for the tibia cortical thickness and area to decrease more in the WM group than in the WL group (P ≤ 0.08). There was a decrease in the periosteal circumference in both groups over time (P < 0.01) and no statistically significant changes in trabecular bone. Circulating total, free, and bioavailable estradiol decreased in the WL group compared with the WM group, and changes were different between groups (P < 0.05). Serum total and bioavailable testosterone increased in both groups (P < 0.01). Serum 25-hydroxyvitamin D increased to a similar extent in both groups (P < 0.05).

CONCLUSIONS

Moderate WL in overweight and obese men did not decrease BMD at any anatomical site or alter cortical and trabecular bone and geometry. Also, despite increased BMD at some sites when maintaining excess body weight, cortical bone showed a trend in the opposite direction.

© 2015 American Society for Nutrition.