Abstract
When a single fat was fed as the sole source of calories and when fat was fed in combination with carbohydrate to the extent of 30% fat and 70% carbohydrate by wt., signifi-cant differences were observed in the length of survival of [female][female] but not of [male][male]. When sucrose was fed as the dietary carbohydrate no significant differences were observed in length of survival on diets containing the various fats, either among [male][male] or [female][female] , but with lactose survival was significantly longer in both on diets containing butter fat and margarine fat than on rations containing corn oil or cotton seed oil. On diets containing fat as the sole source of calories, [female][female] of the Sprague-Dawley strain were more sensitive to variations in dietary fat than those of the U.S.C. strain.