The project was conducted by multi-technologies including both in vitro and in vivo. The propose of this study is to clarify the mechanism of blood glucose control by diet and the foodstuff classification according to their high or low carbohydrate digested solely, and it？？s benefits in control the blood glucose of diabetes was studied.

Using chemical test and in vitro research, the analytic methods were established for 11 types of carbohydrate, which make it easier to understand the chemical and physiological characteristics of carbohydrate and, by these methods, the contents of carbohydrates in 1500 foods, soluble, insoluble and total dietary fiber and resistant starch contents in more than 600 foods were analyzed. This work provided the basic and unique data in China; according to the digested rate and speed of dietary fiber and starch, a new sub-classification was first suggested as soluble, insoluble and total dietary fiber, resistant slowly digested and rapidly digested starch. Furthermore, 160 common foods were selected and the glycemic index (GI) of these foods were measured by 1500 volunteers. The relationship of food type, physical characteristic, composition and processing with blood glucose response were also studied, the results showed that different types of ？？starch？？ and ？？sugar？？ can have different blood glucose response and GI value. All these works provides useful evidence for people to prepare their foods scientifically and prevent from suffering diabetes and other chronic diseases.

The mechanism of how can carbohydrates control body blood glucose level was studied by using the isotope tract technology of natural stable ¹³C. More than 60 healthy volunteers were provided with different types of carbohydrates during different test time, and the metabolized process and blood glucose response during 4, 6, 8, 22, and 33hr were observed. The results showed that resistant starch are characterized by slower digested, lower blood glucose response and energy factor (Atwater factor < 4) as well as lower GI value. The results of animal experiment proved that undigested carbohydrate made many health effect such as decreasing the postprandial glucose and insulin response, increasing the sensitive of tissue to insulin and help to maintain a stable blood glucose level, after they reached colon and fermented there, they can stimulate the growth of probiotics (bifid bacteria and lactic bacteria), and increase the production of short-chain fatty acid as well as decrease the harmful matters (ammonia, amine and hydroxybenzene). These can all do good to human being. All these results can help to understand the mechanism and health effect of undigested starch.

The main application of these results:

1) The databases of 1500 foodstuff on carbohydrate, dietary fiber content and GI value in 160 foods have been used in clinical education, and to rectify the traditional incorrect conception. It proved to be a new and effective method of diet guide, some result showed the blood glucose level was decreased by 15% and about 50% of people can decrease drugs by this way.

2) A ？？Energy Delivered Progressively？？ biscuit (GI<55) was produced by added slowly digested starch and resistant starch, which obtained a production value of 160 million Yuan RMB in the first year and widely welcomed by diabetics and other people.

3) The adequate intake ( AI ) of carbohydrate and dietary fiber were suggested by these studies ,   and promulgated by the Nutritional Society of China in 2000. Now, it is widely used as standard in nutrition filed. The methods of dietary fiber act as a national analytic standard method since 1991 and widely used in the evaluation of food.