Human Heat Production in Relation to Body Weight and Body Surface. III. Inapplicability of Surface Law on Fat Men of the Tropical Zone. IV. General Interpretation of Climatic Influence on Metabolism

Abstract

The minimal heat productions of 50 fat, adult, white Brazilian men, living in Sao Paulo, on the Tropic of Capricorn, are reported. Their ages varied between 20 and 45 years, and their wts. from 62 to 98.8 kg. The data obtained are expressed by the equation C = 3.158 W 0.71, This equation agrees with the theory that the metabolism in tropics is proportional to the metabolically active wt., and not, as in cold climates, to body surface. Therefore the standard proposed for basal metabolism of fat men living in warm climates is: Basal metabolism = [image] = 3.158 with variation of [plus or minus] 14% in 90% and of 22% in 99% of the cases. The higher heat production per kg. of metabolically active tissue may be due to the increased activity of the muscles for supporting and transporting a mass of inactive tissue greater than that of lean men. The different proportionalities of heat production in cold and in warm climates is explained as a "surface effect" appearing only in colder climates, due to an increased heat loss through the body surface. The lowered metabolism in warm climates is also discussed.