Body composition studies play a key role in understanding childhood growth and development. Questions such as whether body weight or lean body mass is the best indicator of when premature babies are healthy enough to go home, or whether very chubby babies are more prone to develop cardiovascular problems as adults, can only be answered with research using precise body composition measurements and appropriate standard reference values.

The CNRC Body Composition Laboratory is the only laboratory of its type in the nation that can provide a complete complement of body composition measurements in all populations ranging from low-birth-weight infants to adults. These high-precision measurements are associated with body water, mineral, protein and fat content. These measurements are used in a wide variety of CNRC research studies and in collaborative projects with other organizations. The laboratory also develops and validates new methods for assessing body composition in children. Data from the body composition laboratory research is also being used to develop age, gender and ethnic-specific body composition standard references, such those for bone mineral content and bone mineral density.

The Body Composition Laboratory uses prompt gamma activation analysis and total body potassium counting to measure whole body muscle mass and lean tissue quality and quantity. Additional methods include stable isotope dilution for measuring the body's water compartments;  dual-energy x-ray absorptiometry (DXA) for measuring bone, fat and lean-body mass; Air displacement plethysmography (BodPod) for determining fat-free mass and body fat; Bioelectrical impedance analysis (BIA) for water and fat ratios; Computed tomography (CT) for measuring fat distribution and bone density; portable Lipometer for measuring subcutaneous fat; and portable Ultrasound for localized bone density measurements.