Effects of feeding rats sucrose in a high fat diet

Rats were fed ad libitum a 40% fat diet containing either 30% sucrose or 30% starch by weight for 8-9 weeks. Insulin levels during a meal tolerance test were significantly greater in rats fed sucrose than in rats fed starch, but serum glucose levels were not affected by diet and tended to decrease as time after the meal increased. Insulin levels during an oral glucose tolerance test were significantly greater in the rats fed sucrose. Serum glucose levels were not affected by diet. Body weights and epididymal and perirenal fat pad weights were higher in rats fed sucrose than in rats fed starch. Serum triglyceride and cholesterol levels were not different. These results show that relatively low sucrose levels in a high fat diet can produce higher insulin levels than starch before and after either a glucose load or a meal. This relative insulin resistance is symptomatic of onset diabetes.