INSULIN INCREASES THE DAILY FOOD-INTAKE OF DIABETIC RATS ON HIGH AND LOW-FAT DIETS

The effects of insulin dose and diet composition on daily food intake were investigated by IV infusion of insulin in doses of 2 to 5 U/day i nto diabetic rats consuming either a high CHO or high fat diet. The da ily food intake of the diabetic rats on both diets increased significa ntly over baseline levels (p < .01) at the low insulin doses and was m aintained at these elevated levels through the 5 U/day dose. Insulin i ncreased the rate of weight gain from 1g/ day during baseline to 2 and 2.5 g/day in high CHO and high fat fed diabetics (p < .01). These res ults show that treatment of diabetic rats with continuous low doses of IV insulin results in a 40% increase in daily food intake regardless of the diet consumed and this increase is accompanied by an increase i n rate of body weight gain. While the high fat fed diabetics were rela tively hypoglycemic, these increases in intake are not the result of i nsulin-induced hypoglycemia, since blood glucose concentrations are si gnificantly elevated when the increases occur at the lower insulin dos es (p < .01). Thus, peripheralinsulin infused at physiological levels stimulates rather than inhibits daily food intake.