PLASMA GLUCOSE AND INSULIN RESPONSES TO ORALLY-ADMINISTERED SIMPLE AND COMPLEX CARBOHYDRATES

The effects of glucose, sucrose and various starches on postprandial plasma glucose and insulin responses in 19 [human] subjects were studied. All carbohydrate loads were calculated to contain 50 g of glucose, and the response to each carbohydrate was tested twice: when given alone in a drink or when given in combination with other nutrients as a meal. Glucose and sucrose elicited similar plasma glucose response curves, but sucrose elicited a somewhat greater (20%) plasma insulin response. Raw starch ingestion resulted in a 44% lower glucose response and a 35-65% lower insulin response than did either glucose or sucrose ingestion. When carbohydrate was given as a meal the plasma glucose responses were 40-60% lower than when the same carbohydrate was given as a drink, while the insulin responses were generally similar. When different cooked starches were compared, plasma glucose and insulin responses to rice were significantly lower (50%) than to potato. The size of the carbohydrate molecule appears to influence the postprandial glucose and insulin responses such that more complex carbohydrates (starches) elicit lower responses. This effect may be related to differences in digestion rather than to differences in absorption.