Abstract: | Twenty-three obese and 17 control subjects were studied after ingestion of a heavy breakfast. Blood samples were drawn before and at 30, 60, 90, 120, 150, and 180 min after the start of the meal. The mean serum insulin level was significantly (p < 0.02) higher in the obese than in the control group throughout the study, whereas the mean blood glucose concentration was significantly (p < 0.02) higher in the obese group at 30, 60, and 90 min only. No significant differences between the two groups were noted in fasting or in postprandial plasma GIP, and it appears that hypersecretion of GIP is not responsible for the hyperinsulinemia seen in obesity. |