The Factors Affecting Normal Basal Metabolism

Abstract

From the groups of men and women it was possible to make selections of a number of individuals who had approximately the same height and weight; on this basis alone can an intelligent comparison be made. Eleven groups, with body weights varying from 67 kg. to 45 kg., were compared and it was found that the average heat-production of all eleven groups, computed on the basis of per kilogram of body weight, was 26.5 calories with men and 25.0 calories with women. The heat output of the men was greater in all but three of the eleven groups.Using again the computation on the basis of the heat production per square meter of body surface we found that the average for the eleven groups showed 819 calories per 24 hours for the men as compared with 770 calories for the women. Of the eleven groups only two had lower values for the men than for the women.On the basis of the foregoing paper, giving the results of a study of athletes, we rigorously excluded athletes from these comparisons, and hence we are dealing here with non-athletic men and women of the same height and the same weight. It is thus reasonable to suppose that the actual body surface of the different groups must have been very nearly the same, and it is not logical to assume that the larger heat production noted with the men was due to a disproportion between the body measurements and the body surface. We believe that these data show a basal metabolism for men some 5 or 6% greater than for women of similar height and weight, and that this increase is due to the fact that in all probability the women, particularly in those groups with the greater body weight, had a much larger proportion of subcutaneous fat than did the men, thus indicating a consequent smaller proportion of active protoplasmic tissue.Although it is well known that the basal normal metabolism of individuals varies considerably, the exact cause for these variations is not known. For many years physiologists have believed that the heat production of a living body is proportional to the surface area. This most helpful hypothesis served to bring order out of chaos in the earlier 105

Beyond the ‘3/4‐power law’: variation in the intra‐and interspecific scaling of metabolic rate in animals

“…Benedict, 1915;Calder, 1984 ;Blaxter, 1989 ;Spaargaren, 1994 ;Burton, 1998 ;Kooijman, 2000 ;Wang et al, 2000;McNab, 2002; see also Section III (3d)]. Although size-related changes in body composition may partially explain the negative allometry of metabolic rate, it is doubtful that they provide a complete explanation.…”

Epidemiologia nutricional

“…A relação entre Freqüência Cardíaca (FC) e GE foi observada no início do século passado por Benedict, que relatou que mudanças na freqüência do pulso estavam correlacionadas com mudanças na produção de calor (Benedict, 1915), o que o fez sugerir que a FC poderia se tornar um método prático satisfatório para a estimativa do metabolismo basal. Atualmente, sabe-se que a freqüência cardíaca de repouso é influenciada pelo nível de aptidão física, o que faz com que a predição da TMB pela FC de repouso não seja adequada.…”

Resting Metabolic Rate of Elderly Vietnamese

“…Studies have shown that RMR decreases with age and that this reduction is dependent on the relationships among energy intake, energy expenditure, changes in body composition, and physical activity [4,24] . On the other hand, aging is also associated with an increase in non-communicable lifestyle-related diseases such as obesity, type 2 diabetes, hypertension and coronary heart disease [25] .…”

“…Indeed, differences due to age and sex exist when BMR values are expressed as calories per unit of body weight or body surface area [4] . Many equations for estimating the BMR of individuals have been formulated and used when actual metabolic measurements are not available [1,5,6] .…”