The Evaluation of Leanness-Fatness in Man: Norms and Interrelationships

Abstract

One of the fundamental characteristics of man's state of nutrition is the composition of his body.Grossly, at least, this means the proportion of his body-weight accounted for by the basic components of blood (subdivided into plasma and cells), interstitial fluid, bone, fat, and 'active tissues' (principally muscles, glands, and nerves).Body fat shows the most striking variations in states of nutrition varying along the emaciation-obesity continuum.The provision of improved methods for a quantitative estimation of the relative fatness is one of the pressing tasks of nutritional science; it is essential both for the evaluation of calorie nutrition and for the establishment of valid estimates of calorie requirements (cf.Food and Agriculture Organization of the United Nations, 1950).In the past, the evaluation of fatness has been based almost exclusively on the individual's deviation from some 'standard' reference weight for his sex, age and height.This conforms to popular ideas; a 'fat' person is thought of as a heavy, overweight individual.Clinical monographs on obesity (Rony, 1940; Rynearson & Gastineau, 1949) devote little or no space to a quantitative evaluation of the degree of obesity.This is defensible if one is concerned only with very marked deviations from normal where, in the absence of oedema, a large increase in weight is likely to mean simply the accumulation of body fat.Experience with animals generally supports the concept of overweight as 'fatness'.A very heavy pig or goose will not only have a larger total weight than a lean animal of the same breed but, at the same time, a disproportionately large percentage of their body-weight will be accounted for in terms of deposited fat.In man, variations in physical activity may alter markedly the composition of the body and disturb the relationship between the relative body-weight and fatness so that the relative body-weight (obtained by expressing the actual weight as a percentage