Dietary Intake of Medium- and Long-chain Triacylglycerols Prevents the Progression of Hyperglycemia in Diabetic ob/ob Mice.

We examined the effects of the dietary intake of medium- and long-chain triacylglycerol (MLCT) on hyperglycemia in diabetic ob/ob mice. Six-week-old male ob/ob mice were fed a diet containing longchain triacylglycerol (LCT) or MLCT for 3 wks. During the dietary treatment, we determined the plasma glucose and insulin concentrations in the fed state once a week. Whereas the body weights did not differ between the two groups, the total intra-abdominal fat mass was significantly higher in the MLCT group compared to the LCT group. The plasma glucose levels in the freely fed state gradually increased during the 3-wk dietary treatment in the LCT but not MLCT group, although the daily food intake did not differ between the two groups. In the fed state, the MLCT group's plasma glucose was significantly lower and their insulin concentrations were significantly higher than those observed in the LCT group (p<0.01). Plasma glucose concentrations at the end of dietary treatment (3rd wk) were negatively correlated with plasma insulin concentrations (p<0.05) and tended to be inversely related to total intra-abdominal fat mass (p=0.08). These results suggest that the dietary intake of MLCT may delay the progression of hyperglycemia in ob/ob mice, possibly through the stimulation of glucose uptake in intra-abdominal fat tissue caused by enhanced insulin secretion.