Bone mineral content and body composition in overweight children and adolescents.

The aim of this study was to analyze the bone mineral content (BMC) of the skeleton and the body composition in lean and fat masses in a population of young overweight subjects, before diet or medical intervention. A total of 496 white youths (298 females, 198 males) were studied. Their body mass index (BMI) values were 29.2+/-5.5 kg/m2 in females and 28.3+/-5.1 kg/m2 in males, corresponding to relative weights (wts) [actual wt, W, divided by the mean wt normal for height (ht), Wi] of 1.55+/-0.24 and 1.53+/-0.24, respectively. Whole-body dual-energy x-ray absorptiometry (DXA) scans were performed (Norland XR36 DXA system) to obtain the total BMC (BMCt), lean tissue mass (LTMt) and fat mass (FMt), as well as the values of the corresponding parameters in arms (a), legs (l), and abdomen (ab). The measured data were compared with theoretical values calculated for Wi. The differences with reference values in LTMt and FMt were sex dependent, and the accretion in FMt, greater in males than in females, yielded a similar FMt/LTMt ratio in both sexes. The wt corresponding to the BMC of the bearing skeleton, lower than the actual wt by about 20%, seemed a reasonable first step to consider in the wt management of these youths.