Men and women who lose weight by reducing their caloric intake may lose bone mineral density (BMD), but people who shed pounds by exercising do not, according to the results of a study published in the Dec. 11/25 issue of the 

Dennis T. Villareal, MD, of Washington University School of Medicine in St. Louis, and colleagues studied the effects of weight loss on BMD in 48 adults. Participants who followed a calorie-restricted diet lost an average of 10.7% of their body weight after 1 year. Participants in the exercise group lost an average of 8.4% of their body weight, and participants in the control group who received information on healthy lifestyles upon request maintained their weight at 1 year. 

Individuals in the caloric-restriction group also lost an average of 2.2% of their BMD in the lower spine, 2.2% at the hip, and 2.1% at the top end of the femur. By contrast, there were no significant changes in BMD in the exercise or control groups. Bone turnover increased in both weight-loss groups. 

Villareal DT, Fontana L, Weiss EP, et al. Bone mineral density response to caloric restriction-induced weight loss or exercise-induced weight loss: a randomized controlled trial. 

Men and women who lose weight by reducing their caloric intake may lose bone mineral density (BMD), but people who shed pounds by exercising do not, according to the results of a study published in the Dec. 11/25 issue of the Archives of Internal Medicine.