DU BOIS: BASAL ENERGY REQUIREMENT OF MAN 347 



it does not seem reasonable to believe that the introduction of the 

 plant occurred within the period of exploration of the Pacific by 

 Europeans. Nothing need be said of the reports of the early 

 explorers who found sweet potatoes already in the islands. 



If the sweet potato had come to the Polynesians in recent 

 times from an outside source it is practically inconceivable that 

 the same name should have been distributed and adopted in so 

 many islands. In this respect there is a notable contrast with 

 the many distinct names for sweet potatoes among the native 

 tribes of the American continent. The many traditions or myths 

 regarding the kumara in the Pacific may mean nothing to which 

 any definite significance can be attached, but at least they show 

 how deeply the kumara was embedded in the existence of the 

 islanders. The sweet potato, like the coconut palm, had rela- 

 tively greater importance among the Polynesians than in other 

 parts of the world. 



PHYSIOLOGY. — The basal energy requirement of man. 1 Eugene 

 F. Du Bois, M.D. 



It is not too much to say that the science of nutrition is founded 

 on the study of the basal energy requirement. Therefore it 

 seems advisable to spend our time today on this aspect of the 

 subject as an introduction to the subsequent lectures of the 

 series. First we shall consider the definition of the term, basal 

 energy requirement, next the manner in which it is studied, and 

 finally the factors by which it is influenced in health and disease. 



The energy requirement of a man is represented by the number 

 of food calories, or heat units, required to balance the calories of 

 his heat production. The two are equal, because food oxidized 

 in the body gives off just as much heat as food burned outside 

 the body. The basal requirenent is the minimal requirement 

 or lowest heat production, and this condition is found only when 

 an individual is lying down, at complete rest in the morning, 



1 A lecture delivered before the Washington Academy of Sciences, April 7, 

 1916. From the Russell Sage Institute of Pathology, in affiliation with the Sec- 

 ond Medical Division of Bellevue Hospital, New York. 



