Effect of diet on body temperature during sleep in the cold

¹ Physiology Branch, Environmental Protection Research Division, Quartermaster Research and Engineering Command, U. S. Army, Quartermaster Research and Engineering Center, Natick, Massachusetts

Thirteen young soldiers were divided into two groups and fed liquid diets of similar caloric content but of different composition. One group was fed a normal, high-fat, high-carbohydrate and normal diet in the first, second, third and fourth weeks, respectively; the second group was fed a normal, high-carbohydrate, high-fat and normal diet during the same periods. Three meals were eaten at 8 a.m., 5 p.m., and 10:15 p.m., at which times 30, 30 and 40% of the daily calories were consumed. Measurements of skin (11 points) and rectal temperatures were made at one-half-hour intervals throughout the night when the subjects were in sleeping bags at an ambient temperature of –30°F. Protection against the cold was designed to be inadequate to maintain thermal comfort. Composition of the diet had no effect on rectal, mean weighted skin or toe temperatures throughout the night with a few exceptions. No physiological significance is ascribed to these exceptions since the differences were very small. It is concluded by comparison with a previous study that caloric content rather than composition of the diet is the important factor in decreasing rates of body cooling of men sleeping in the cold.