We have focused on two topics in body composition research. The first is basic: we must quantitatively define the interrelationships of the body compartments to one another in health before studying these relationships in disease. The precisions now available can enable us to get to do this work, over the full range of age, race, and occupational diversity. The second direction is more modest and more technical, but nonetheless important. It is the calibration and validation of surrogate measurement methods suitable for field research conditions, doctors' offices, intensive care units, etcetera. Our methods have advanced in fundamental ways. We have an obligation to see them applied effectively.