After we eat foods with high GI value (high glycemic index) such as sugar and starch, blood sugar will rise rapidly, which will prompt the pancreas to secrete insulin to reduce the blood sugar concentration and convert it into energy needed in life. However, if we consume too much sugar and starch, insulin will convert excess sugar into fat and store it in the body, which will easily lead to obesity. Therefore, when we eat foods with low GI value (low glycemic index), we slow down the rate of blood sugar rise, reduce the secretion of insulin and reduce the formation and accumulation of fat, which is the so-called "low GI diet", also known as "low insulin diet".

It is also worth noting that only a single food will have a certain GI value, and the GI value of mixed food is difficult to calculate. Food is easy to add other sauces or spices during cooking, which may also affect the GI value of the food itself. The amount of starch in food, the cooking method of food, the length of cooking time, the amount of fiber content, the types of nutrients, etc.

The seemingly healthy low GI weight loss method may be counterproductive because of wrong cognition. Many people have a misunderstanding about low-GI foods, and think that low-GI foods are not fattening, but in fact this is not the case, because foods with low GI values are not necessarily low in calories. If you eat too much low-GI foods, the total calories will still be high, which will also lead to obesity. Therefore, it is necessary to recombine the quality (GI value) of food rather than the quantity of food within a fixed total calorie range, in order to effectively play the role of reducing weight with low GI.

Although the media once reported with the sensational headline "Eating big fish and big meat can also lose weight", is there such a good thing in the world? Some diet packages or recipes with low GI in the market may not be effective or conform to the principle of balanced diet, and may also take too much lipid and protein invisibly (in order to reduce the intake of starch, the intake of protein and oil is greatly increased), which will cause physical load and even cause cardiovascular diseases.

The low GI diet was originally designed for diabetic patients to control their blood sugar through diet, which is not necessarily suitable as a way to lose weight. Weight loss still depends on long-term exercise in order to maintain a good figure. It is best not to trust the weight-loss products in the market, so as not to lose weight but damage the body.