The present thesis has drawn on a wide range of studies employing a variety of methodologies, aiming to explore the importance of body composition and morphology in relation to health and disease in adults, with a principle consideration of the need for health promotion. To achieve these aims, a series of hypotheses were postulated and a number of research questions were asked, followed by hypothesis testing and data analyses to gain new understanding, and to establish firmly the associations of body morphology with health and disease. Recognising the limited success in reversing the increasing trends in overweight has prompted the need to design new strategies in promoting public awareness of the risk of ill health associated with overweight and central fat distribution. These studies were carried out in this context to develop simple methods for assessing body composition, to enable health professionals and general public to assess and identify people with increasing health risks associated with overweight and increased intra-abdominal fat accumulation.