The Energy Expenditure and Food Intake of Individual Men

Abstract

Within the last 15 years an interest in the importance of calorie expenditure and its relationship to intake has begun to reassert itself after a long interval of time. I3roadly speaking there have been two reasons for it: the first has been a desire to find out more about the mechanisms which relate intake to expenditure-what regulates appetite, in fact-and the second an interest in industrial and field physiology. The first detailed study of energy expenditure and dietary intake was made by Bedale (1922-3). Bedale measured the oxygen consumption of IOO schoolchildren at twentyfive different activities and the time they spent on these activities. Wiehl (1944) investigated by a diary and interview technique the activities of high-school boys and girls in the United States over a 2-day period. These activities were listed under the headings of sleeping, sitting, and light, moderate and severe exercise, and the mean expenditure agreed very well with the intake, but the individual intakes varied from 50 to 190 yo of the expenditures. Keys (1945) criticized these findings as showing the fallacy of computing requirements in this way, and pointed out that individuals who were not rapidly gaining or losing weight must be in calorie balance. This is true, but they need not be in daily balance. Fox (1953) estimated the calorie expenditure and the food intake of members of a village in the Gambia over a period of a year. He measured the oxygen consumption at various tasks and recorded the time spent on the different occupations. Owing to a period of food shortage which coincided with the heavy farming work in preparation for the forthcoming harvest, calorie balance was only achieved over a matter of months, with corresponding losses and gains of weight.