Small intestinal effects of starchy foods

Recent dietary guidelines advocate increased starch intake, but it is not clear as to how the increased intake of starch should be achieved. Recent data suggest that the quality of starch as well as its quantity is important in determining the biological effects of high carbohydrate diets. The quality of starchy foods can be assessed by their rates of digestion, which in turn are related to their glycaemic responses. Many factors affect the rate of digestion of foods and these are probably related to alterations in the chemical structure or nature of the starch. The incorporation of slowly digested, low glycaemic index foods into the diets of healthy subjects and individuals with diabetes and hyperlipidaemia is associated with the predicted reductions in postprandial glycaemic responses and with reductions in insulin secretion and blood lipids. In the past, the aim of starch processing has been to increase digestibility and improve absorption. However, it is now suggested that the use of more slowly digested starchy foods may have positive health benefits.