Some foods raise your blood sugar a lot. Other foods with the same amount of calories don’t. I have seen the graphs in The New Glucose Revolution: The Authoritative Guide to the Glycemic Index — the Dietary Solution for Lifelong Health, , but they do not show a long period of digestion for the low glycemic foods. There is no explanation given to explain why the same amounts of calories result in substantial differences in the total amounts of blood sugar created. Will you tell me why this is so?

The relationship of blood sugar to dietary intake is a complex affair. To rather oversimplify it fat, which has the highest caloric density of all foods does not contribute directly to blood sugar levels.Fat also delays the onward passage of food from the stomach to the intestine for further digestion. Protein, on the other hand, which is more or less equivalent in calories to carbohydrate, can contribute to blood glucose through a process known as gluconeogenesis, but again this is for the most part only brought into action when blood sugars are low. Thus it has little immediate effect on blood sugar.

The result is that the immediate contribution to blood sugars after meals is dependant predominantly on sugars and starches in the diet. Glucose and cane sugar are absorbed very quickly; but there is a lot of variation in starch absorption. Potato starch, for example, is rapidly hydrolysed and absorbed as glucose whereas other starches such as those in dietary supplements like NiteBite that are designed to contain nocturnal hypoglycemia are very slowly converted to glucose.

In type 2 diabetes, impaired insulin secretion and sensitivity may also distort the blood sugar response to carbohydrate intake. Drugs like Precose (acarbose) are designed to delay the intestinal breakdown of starches.

DOB