HEAT OF HUMAN BODY

Greymouth Evening Star, 3 October 1931, Page 3

HEAT OF HUMAN BODY

VALUABLE RESEARCH WORK. Heat production capacity of the human body is the subject of research at the Carnegie Institution at Washington. The results of this work have already proved of definite practical value, notably in the investigation of diseases. The director of the Nutrition Laboratory at the institution, Dr F. G. Benedict, in an article on the subject states that in the last ten years several hundred normal men and women have been measured, and together with their heat production capacity, their height, weight and age have been recordedFrom an elaborate statistical analysis of these data four primary factors have been noted each independently affecting basal metabolism—production of heat. These are weight, height, age and sex. It is not possible to compare uncritically the heavy man with the short and small man, for this brings in two factors, weight and height- But when two men of the same height are compared, it is fpund the heavier man will produce more heat than the lighter man of the same height. Thus it is seen that weight alone increases the heat production. Height also raises the heat production.

It is not necessary to eat food in order to develop heat in the body; life still goes on, and the body itself furnishes the energy. Animals subsist for an incredible time without taking food, always drawing upon their body fat. The steer has fasted fourteen days, the dog as long as sixty days, and even the white rat twenty days, and yet all these animals recovered promptly when feeding was resumed. After such a fast these animals are not as active as before fasting, but they are by no means dead. They are ready to take food, and although they cannot do much heavy work, it is surprising what they can do. I’or example, the man at the thirty-first day of fasting delivered an oration for thirty minutes with strong gesticulations; he also danced and ran upstairs. . The cold-blooded animals furnish some most astonishing illustrations of the ability to subsist on body material for a long time without feeding. The python lies quietly, almost ineit. It has a low body temperature, a low respiration rate and a low heart rate. Its whole level of activity, and therefore the heat production, is very lowThe reserves of body fat are slowly drawn upon. The python may last without food for as long as two or three years. Dr Benedict proceeds to show that heat production is lowered by age. A man, for example, at twenty-five years of age in full prime of physical vigour, produces more heat than a man of the same height and weight but seventy years of age. The fires of life are burning at a somewhat lower ebb in old age. Age is an important factor to take into consideration whenever basal metabolism is being measured or considered.