This study examines the effects of weight loss by caloric restriction (WL) and aerobic exercise plus weight loss (AEx+WL) on total and regional bone mineral density (BMD) in older women. Healthy, postmenopausal women [age 63 ± 1 (SE) yr] not on hormone-replacement therapy underwent 6 mo of WL ( n = 15) consisting of dietary counseling one time per week with a caloric deficit (250–350 kcal/day) or AEx+WL ( n = 15) consisting of treadmill exercise three times per week in addition to the weight loss. Maximal aerobic capacity increased only in the AEx+WL group ( P < 0.001). Body weight, percent fat, and fat mass decreased similarly in both groups ( P < 0.005), with no changes in fat-free mass. Total body BMD (by dual-energy X-ray absorptiometry) decreased in both groups ( P < 0.05). Femoral neck, Ward’s triangle, and greater trochanter BMD decreased in the WL group ( P ≤ 0.05) but were not significantly different after AEx+WL. L2–L4BMD did not significantly change in either group. Thus WL and AEx+WL both result in losses of total body BMD; however, AEx+WL appears to prevent the loss in regional BMD seen with WL alone in healthy, older women. This suggests that the addition of exercise to weight-loss programs may reduce the risk for bone loss.
Estimating regional bone mineral density-based T-scores using clinical information; tools validated for postmenopausal women in Sri Lanka
