Health Promotion Board, Singapore, Republic of Singapore
Body composition information on humans can be collected at various levels, such as atomic, molecular, cellular, tissue, or whole-body level (1). In the case of obesity, the main component of interest is body fat, at the tissue [adipose tissue obtained by computer tomography (CT) or magnetic resonance imaging (MRI) scanning] or molecular level [body fat mass or body fat percent as assessed by densitometry or dualenergy x-ray absorptiometry (DXA) scans]. In addition, the distribution of fat over the body is important. The latter can be evaluated by CT or MRI scans or by anthropometry.