Circadian eating and drinking habits in alloxan diabetic rats.

Eating and drinking habits were studied in control and alloxan diabetic rats of up to 12 months' duration of diabetes, with emphasis on the hour-to-hour circadian pattern and the relationship between eating and drinking. In contrast to previous studies food and water intake started to increase immediately after alloxan injection possibly because of avoidance of alloxan induced acute renal insufficiency by kidney protection during alloxan injection. A biphasic circadian pattern of food and water intake was seen in both diabetic and control rats, but day-time eating and drinking were practically absent in controls in contrast to diabetic rats. The diabetic animals' meals and drinking bouts were significantly longer than the controls and the frequency of drinking bouts, but not of meals, was increased. Drinking was mainly associated with meals in both diabetic and control rats. Insulin treatment in diabetic rats partly normalized daily food and water intake.