Effect of dietary composition on insulin receptors in normal subjects.

Six normal subjects were placed on a high carbohydrate diet (80%) and a high fat diet (60%) for 2 weeks each. Glucose tolerance testing with plasma immunoreactive insulin levels was performed along with insulin receptor quantitation after a control period and after each of the dietary manipulations. Despite improved carbohydrate tolerance and decreased plasma immuno-reactive insulin after the high carbohydrate diet (evidence for increased insulin sensitivity) insulin receptor number and affinity were unchanged. These studies suggest that the increased insulin sensitivity induced by a high carbohydrate diet is due to some adaptive change in postreceptor activity. Manipulations of dietary composition fail to alter insulin binding to peripheral mononuclear cells.