Analysis:

Eat well before meals.

Eat fruit before meals to lose weight, and eat fruit after meals to help digestion.

When is the right time to eat fruit in a day?

1. Eat fruit for half an hour after meals: it helps digestion and absorption. The main components of sugar in fruit are fructose and glucose, which can be directly absorbed by small intestine without digestion and decomposition. Other foods containing starch and protein ingredients, such as rice, pasta, meat, etc., need to stay in the stomach for a period of time for digestion. If you eat fruit immediately after a meal, the slow-digested starch protein will block the fast-digested fruit and all the food will be mixed in your stomach. When the fruit is at a high temperature of 367 degrees Celsius in the body, it will produce fermentation reaction, even corruption, flatulence, constipation and other symptoms, which will bring adverse effects to the digestive tract.

2. Eat fruit before meals: the need to lose weight affects appetite and normal digestion and absorption. Studies show that if you eat some fruits or drink 1-2 cups of juice 20-40 minutes before meals, you can prevent obesity caused by overeating smoothly and painlessly. Because fruit or juice is rich in fructose and glucose, it can be quickly absorbed by the human body to meet the urgent "thirst" of blood oxygen, and the crude fiber in fruit can also make the stomach feel full. In addition, eating fruits and vegetables before meals can significantly reduce the demand for fatty foods, thus indirectly preventing the adverse consequences of excessive fat accumulation in the body.

Experts suggest that persimmons, pomegranates, lemons, grapes, sour pomelo, bayberry and other fruits with much tannic acid should not be eaten with seafood rich in protein and minerals, such as squid, lobster and algae. Tannic acid will not only reduce the nutritional value of seafood protein, but also easily combine with calcium and iron in seafood to form a indigestible substance, which can cause nausea and vomiting. Therefore, after eating these seafood, you should enjoy the fruit after 2-3 hours.

Don't heat the fruit after juicing.

Is it better to eat fresh fruit or juice?

Professor Luo: There is no difference between fresh fruit and freshly squeezed fruit juice in nutrients such as vitamins, protein, fat, sugar and trace elements, but in the processing of freshly squeezed fruit, a lot of dietary fiber necessary for human body is lost. Dietary fiber has some important physiological functions, such as relaxing bowels to prevent cancer, lowering serum cholesterol, lowering postprandial blood sugar and adjuvant treatment of diabetes.

Many people have the habit of heating and drinking fruits after juicing, which will destroy vitamins to varying degrees.

Because the chewing function of the elderly and infants is poor, freshly squeezed juice is very suitable for eating, but it is best to eat the solid residue left after juicing, so that nutrients will not be lost. After all the deciduous teeth are pulled out, children should eat some fruits rich in fiber and with certain hardness to increase chewing power and promote the development of gums, jaws and facial bones. Drinking fruit juice is easy to make children's teeth lack exercise, their teeth are not arranged neatly, and their upper and lower teeth are misaligned, which is not good for health.

Imported fruits and domestic fruits: similar nutrition

Are imported fruits more nutritious than domestic fruits?

At present, there are 100 kinds of foreign fruits in the fruit market, and consumers are familiar with raisins, snake fruits, American navel oranges, crystal pears, kiwis, lemons, mangoes, longan and pitaya. There is little difference in nutritional components between imported fruits and domestic fruits, but there are some differences in appearance, texture and taste from domestic fruits.

For example, American navel orange, native to the United States and Australia, is similar to Fengjie navel orange in Chongqing. It's big, full of water, crisp and sweet. But the skin is rough, not as smooth as domestic navel orange, and the fiber is thicker, not as fine as domestic navel orange. Crystal pear originated in Japan. Although it is only one word apart from the Crystal Yali pear in Hebei, its appearance and taste are quite different. Crystal pear is very big, and it feels like falling in your hand. It is dark yellow. Crystal pear is unique in that its shape is not like a pear, but like an apple, which is particularly crisp to eat.

Will the nutritional components of fruits decrease after cold storage?

Professor Luo: Fresh fruits are stored in the refrigerator, and the temperature in the refrigerator is about 0- 10℃, which can maintain the quality and flavor of fruits and prolong the shelf life of fruits. But not all fresh fruits are suitable for cold storage, and attention should be paid to the cold storage period. For example, the optimum storage temperature of bananas is 13.3- 14.4℃. If the temperature is too low, hypothermia will occur and bananas will turn black. When watermelon is cut and refrigerated for a long time, a film will form on the surface of the pulp, and cold air will be absorbed by the pulp. Eating a large number of watermelons refrigerated for a long time will hurt the spleen and stomach and cause pharyngitis. Children's digestive function is poor, and eating more frozen fruits can easily cause anorexia, abdominal pain, vomiting and diarrhea. Generally, the cold storage period of peaches is 5 days, grapes are 7 days, and strawberries are 2 days.

Expert advice: it is best to keep the intake of 1 fruit every day.

Patients with gastric and duodenal ulcers should not eat fruits containing more organic acids, such as plums, hawthorn, bayberry and lemon, if their stomach acid is too much.

Patients with myocardial infarction should not eat apples, persimmons, lotus seeds and other fruits containing more tannic acid, so as not to have a strong astringent effect, aggravate constipation, and lead to repeated attacks; Patients with heart disease and edema should not eat watermelon, coconut and other fruits with more water content, so as not to increase the burden on the heart and aggravate edema;

People with diabetes should eat less fruits with high sugar content, such as pears, apples, bananas, lychees, longan, dates and watermelons. If you eat1000-2,000 grams of watermelon at a time, it is equivalent to adding 50- 100 grams of sugar in a short time; Patients with nephritis, hypertension and other diseases must not eat more bananas;

Hepatitis patients eat more fruits containing more vitamin C, such as oranges and fresh dates, which is beneficial to the treatment and recovery of hepatitis.

People who often have dry stools can eat more peaches, bananas, oranges and so on. Because these fruits have the effect of relieving constipation, persimmons contain a lot of persimmon gum, which will aggravate constipation if eaten too much; People who often have diarrhea should not eat more fruits that can relieve diarrhea. You can eat some apples properly, because apples have a astringent effect.

There is an English proverb: "The fruit in the morning is gold and silver from noon to 3 pm, copper from 3 pm to 6 pm, and lead after 6 pm."

A person concerned at the Japanese Horticultural Experiment Field gave a fresh explanation: "Strictly speaking, it doesn't matter when the fruit is eaten. But for people who can't eat breakfast, it's easy to eat fruit. Fructose can be converted into heat in a short time, giving the human body the necessary energy supplement. In addition, fruits can supplement vitamins and minerals. In addition, fruits picked in the morning when the temperature is low will last longer. The temperature is high at noon, and the nutrients of the fruit may be absorbed by the trunk, so it is better to pick it in the morning. "

However, Professor Chai Tian of Japanese Xinglin University reminds people: "Fructose is most easily converted into neutral fat. For obese people, it is best to exercise after eating fruit in the morning. "