The Effects of a High Fat Diet in a Temperate Environment

A group of eight men living in a cool environment and doing work consisting mostly of laboratory procedures subsisted for 9 days on a high fat diet (pemmican) providing 71% of the calories from beef fat and 2% from carbohydrate. Four controls subsisted on a diet adequate in all respects and providing 30% of the calories from fat. The utility of pemmican alone as a field ration for ordinary men was very poor because of the inability of all but one subject to eat enough of it. Morale deteriorated on the diet and most of the men resigned themselves to semi-starvation for the duration of the diet, mainly because of the nauseating taste. Nevertheless, scores in a physical fitness test remained practically constant. Significant biochemical and physiological changes occurred, even in the one man who ate adequate amounts of the pemmican. These included: (a) an average weight loss of 5.9 kg, much of it water; (b) change in water balance, with loss of body water; (c) salt depletion as measured by serum and urinary chlorides; (d) marked ketonuria; (e) alteration in the glucose tolerance curve, with prolongation of the rise but without alteration of the maximum; (f) alteration in tolerance to a given dose of insulin with much increased physiological reaction and prolongation of the decrease without alteration in the minimum; (g) increased retention of bromsulfalein. All of the above abnormalities were repaired in 3 days of normal diet. Measurements showing no significant changes include: (a) serum protein; (b) serum non-protein nitrogen; (c) serum ascorbic acid, (d) serum cholesterol; (e) fasting blood glucose; (f) urinary excretion of thiamine, riboflavin and ascorbic acid; (g) basal metabolic rate; (h) phenolsulfonphthalein test of kidney function. This work should not be taken to apply to all high fat diets, but at this point we do not know why there appears to be a difference between a diet of pemmican and a diet of fresh meat and fat.