The Japanese people are not genetically predisposed to be low Glucose tolerant. However, during their traditional diet, when rice and other carbohydrates were the main staple of the diet, the average person's Glucose level was quite low. Today, the average Glucose level is around 3.5 grams per deciliter (less than one tenth of a cup). So, the challenge is to get back to the norm.
A number of diabetics find that their long term health problems are better controlled if they follow a very strict low-carb diet. Many people who are Glucose intolerant have found that following a high-protein, low-fat, low- carbohydrate diet has greatly improved their glucose levels. In addition, if you are a true Glucose Antibody, i.e. those people who have blood tests which indicate that they lack Glucose uptake into their cells, then you will benefit from a strict low-glycemic diet.