Duodenal and ileal lipid suppresses postprandial blood glucose and insulin responses in man: possible implications for the dietary management of diabetes mellitus.

Infusion of lipid into the ileum delays the transit of a meal through the stomach and small intestine and could therefore influence the rate and degree of nutrient absorption. Experiments were carried out on human volunteers to investigate the effect of infusion of lipid into either the duodenum or ileum on blood glucose, insulin and gastric emptying after ingestion of a mashed potato meal. Infusions of lipid into either the duodenum or the ileum significantly reduced or abolished the immediate postprandial rises in blood glucose and insulin and significantly delayed gastric emptying. Blood glucose and insulin rose shortly after the lipid infusion terminated. Addition of corn oil to a meal of mashed potato also reduced blood glucose and insulin and delayed gastric emptying. Intestinal lipid can thus modify the glycaemic and insulinaemic responses to a meal, and this modulation probably explains the reduced metabolic responses to a meal containing fat compared with a fat free meal. This principle could be of value in the dietary control of diabetes mellitus.