Body composition studies are used in a wide variety of fields including human biology, medicine, sports science, epidemiology, and nutrition. They may be used to predict later body composition from childhood measures, to detect bone density loss in the elderly or in athletes under heavy training, to assess obesity in children and adults, and to investigate the likely effects of malnutrition. Recently, there has been a resurgence of interest in the field of body composition, together with rapid development of a whole new range of assessment techniques. In this volume, new and old techniques are evaluated and future developments and aims are discussed. The chapters assume little background knowledge, and will therefore be valuable to nutritionists, biologists, clinicians and medical physicists alike.