Preserved fruit refers to cold fruit, which has the effect of clearing away heat and toxic materials, but you can't eat more, otherwise it will be harmful to your health. Chinese medicine believes that all foods can be divided into four types according to their nature, namely "cold, cool, warm and hot", which is called "four qi" or "four products" by Chinese medicine. The same is true of fruits. For example, we often say that "watermelon is cold, and eating too much will cause diarrhea", which refers to the food characteristics of watermelon-cold.

Common cool fruits are cantaloupe, kiwi fruit, watermelon, pear, melon, banana, persimmon, grapefruit, water chestnut, pitaya and so on. Generally speaking, people with hot constitution have vigorous metabolism in summer, sweat more, often blush, dry mouth, fidgety mood, easy constipation, especially like to eat cold things, so people with hot constitution can eat some cool fruits appropriately. However, people with cold constitution or people with cold constitution are not easy to eat, especially women who have menstruation can't eat more. The "sex" of food is mainly distinguished according to the different attributes of food in diet conditioning. For example, food has four different properties: cold, cool, warm and hot, which are called "four natures" of food.

Later, on the basis of the four natures, the equality was added. It belongs to neither cold nor hot, neither cold nor hot, it belongs to cold and hot, and warm and cool. Only plain food can provide people with long-term consumption and nourish people's spleen and stomach. Of course, food nowadays pays attention to reasonable collocation, that is to say, hot food can be matched with cold food and eaten according to one's own physique. Among fruits, those with cool nature also have heat-clearing effect, such as pears, watermelons, strawberries, bananas, grapefruit, pitaya, water chestnuts, etc., those with warm nature such as litchi, bayberry, longan and durian, and those with flat nature such as apples and oranges.

In fact, this is not about the nutrition in food, but only about the nutrients contained in food. Although many people say that fruit is cool and dare not eat anything, fruit itself is rich in water, high in vitamin C, dietary fiber, and various minerals and phytochemicals. Therefore, eating fruit every day is good for balancing diet and preventing various chronic diseases. The Dietary Guide for China Residents recommends eating 200-350 a day.