U.S. Army Medical Research Laboratory, Office of the Surgeon General, Fort Knox, Kentucky
Quartermaster Climatic Research Laboratory, United States Army, Lawrence, Massachusetts
U.S. Army Quartermaster Research and Development Center, United States Army, Natick, Massachusetts
U.S. Army Research Institute of Environmental Medicine, United States Army, Natick, Massachusetts
Those interested in perusing the various investigations conducted by personnel from these agencies should consult their respective report series because not all summaries of the sponsored work have appeared in the open scientific literature. It is hoped that many of the reports remain on file.
Between 1941 and 1946, reliable data were collected of food intakes for physically fit, active ground troops who chose their foodstuffs from the rations provided in temperate, mountain, desert, jungle, arctic, and subarctic areas in North America, Europe, and Asia. Dietary surveys and Army ration trials had been conducted intermittently throughout World War II. Johnson and Kark (1947) summarized these data and presented a brief critical review of the nutrition of U.S. and Canadian soldiers in 1946 based on their more comprehensive report prepared for the U.S. Army's Quartermaster Food and Container Institute for the Armed Forces (Johnson and Kark, 1946). Their summarized nutrient intake data from several studies appear in Table 6-1. A somewhat abbreviated table was subsequently published in 1947 (Johnson and Kark, 1947) (Table 6-2). They clearly demonstrated the inverse relationship of caloric intake with mean local temperature as ascertained from the dietary surveys and ration trials. Groups of from 50 to 200 men were represented in each study. A consistent reduction in voluntary kcal intake per °F over the range-20° to 100°F was found. Their regression equation was: kcal per day = 4660-15.9 T (°F) where T is the mean external temperature. The higher the mean environmental temperature the lower the voluntary kcal intake, and the lower the mean environmental temperature the higher the voluntary kcal intake.
Johnson and Kark (1947) concluded that the large difference in caloric intake could not be explained by differences in basal metabolic rate (a difference of 10 to 20 percent at most), body weight, or type of activity because they contended the ground troops carried out similar tasks in each environment. Unfortunately, they had little data to confirm no differences in physical activity by the troops at the several garrisons. Nevertheless, Johnson and Kark stated that the caloric expenditure for a given task was greater in the cold than in warm climates because of the ''hobbling effect'' of arctic clothing and equipment. They also concluded that more body heat