Entropy principle for human development, growth and aging.

Entropy productions within nude subjects in respiration calorimeters are calculated from the corresponding energetic data obtained by Du Bois et al. (1952, J. Nutr. 48, 257-293.). The entropy production for men is constant at environmental temperatures from 24-34 degrees C. The metabolic entropy production comprises 98.6% of the total entropy production. The entropy production for women shows a minimum at 30 degrees C (the middle of the neutral zone), a small rise in the cold zone and a trend toward a rise in the warm zone; the average entropy production for women is 8.7% smaller than that for men. The entropy production rises from 0-2 years of age, and decreases rapidly from 2-25 years of age and then gradually to 85 years of age. The entropy production does not seem to achieve a minimum or a level in the lives of men and women. Based on these results, a three-stage hypothesis of entropy production in human life is proposed.