Many people think that unsweetened foods contain rather low content of sugar and they can not endanger the human health seriously. In fact, much sugar is hidden in foods, whether the foods are sweet or not. 

Most of the hidden sugar is contained in puffed foods and instant pastes like walnut powder. Puffed foods and instant pastes contain low content of oily fat and high content of starch, so many people think these foods are healthy to eat. In fact, there is no dietary fiber contained in these foods which can restrain the increase of blood sugar. After the starch enters the human body, the level of blood sugar can be greatly increased. Some vegetables like potato also contain high content of starch. The starch contained in them can be rapidly transformed into glucose inside the human body. In addition, many people judge the content of sugar contained in fruits according to the sweetness of fruits. It is also improper. There is no relationship between sugar content and the sweetness. For example, watermelon is so sweet, but its sugar content just reaches 4.2%; kiwi tastes sour, but its sugar content reaches as high as 10%. Some other fruits like apple and banana also contain high content of sugar. The high content of hidden sugar is also contained in bread, yogurt, prune and catchup. For example, each 100 grams of bread contain 10 to 20 grams of white sugar. A lot of sugar is added into prune during the production process in order to restrain the formation of bacteria.

In order to help people judge the content of sugar correctly, three tips are introduced here. The first tip is to look at the food label carefully. The compositions of food are arranged in the label according to their contents. If the compositions like white sugar, glucose and high fructose corn syrup are ranked ahead, the content of hidden sugar can be probably high. It is necessary for people to eat such foods moderately. The second tip is to choose fruits correctly. When people buy fruits, they should choose the ones with low maturity. The fruits with low maturity contain low content of sugar and high content of nutrients. The third tip is to increase the intake of vegetables containing abundant dietary fibers. Porridge and cooked rice can increase the blood sugar inside the human body. It is necessary for people to eat some vegetables containing dietary fibers and protein at the same time.