Nutrient interaction in relation to glycaemic and insulinaemic response

Although it is known that protein, fat and fibre reduce the postprandial glycaemia following an oral carbohydrate load, the nature and extent of interaction of different nutrients with one another in this respect is not well understood. The present study was designed to explore systematically the glycaemic and insulinaemic response to glucose (G) alone, or in combination with one or more of the following: casein (CS), maize oil (MO), cellulose (CL) and pectin (P). Besides 100 g G, eleven isoenergetic and six isocarbohydrate meals were studied on healthy adult males using an incomplete block design. Addition of other nutrients to G led to a lowering of the glycaemic response. The lowest glycaemic responses were seen in case of meals containing the largest number of nutrients. P was more effective in reducing postprandial glycaemia than CL. As in case of glycaemic response, low insulinaemic responses were also associated with P-containing meals, and meals containing the largest number of nutrients. But unlike in case of glycaemic response, there was a tendency for elevation of the insulinaemic response in case of CL-containing meals. The degree of attenuation of glycaemic response observed with meals containing several nutrients was roughly predictable on the basis of the attenuation observed with meals in which only one nutrient had been added at a time to G. But the glycaemic response of natural foods is unlikely to be predictable on the basis of their nutrient composition because of the overriding influence of several other factors such as physical form, cooking, processing, storage and antinutrient content of the food.