Drinking coffee in moderation will accelerate metabolism, promote digestion, improve constipation and improve rough skin. Coffee will accelerate the burning of calories and achieve the effect of losing weight. This theory is basically correct, but burning calories won't make you lose much weight. If sugar and creamer are added to coffee, the calculation of calories is even more inconsistent with the principle of losing weight. It is unscientific to drink too much coffee. By the way, introduce the knowledge about coffee for your reference-many research reports show that caffeine is actually beneficial to the human body in many ways. For example, coffee can stimulate athletes to create better results. At the same time, it is found that the moderate stimulation brought by coffee is beneficial to many daily activities, such as reducing work pressure and refreshing yourself when preparing homework. Drinking coffee in moderation will not affect human health, but it is a good refreshing drink with almost no side effects. First, understand caffeine Caffeine is a mild stimulant, which contains a small amount of caffeine in our daily drinks such as tea, cocoa and chocolate. Carbohydrate drinks such as cola and some anesthetics also contain caffeine. It can accelerate human metabolism and keep people awake and alert. The refreshing effect of coffee is particularly popular. Caffeine can stay in the human body for several hours, and its influence on the body is suitable for people. Some people will lose sleep after drinking coffee at night, some people will be nervous and overexcited after drinking too much coffee, but many people will not be affected at all. Once we know the human body's reaction to caffeine, we can use it to meet our own needs. Reviewing before the exam or drinking a cup of delicious coffee while driving for a long time will definitely reduce fatigue. Caffeine in coffee is insoluble in cold water but soluble in hot water. It can stimulate cerebral cortex, eliminate drowsiness, enhance touch and thinking, regulate heart function, dilate renal blood vessels and induce diuresis. However, caffeine is not limited to coffee. Usually, a cup of coffee 100cc contains 60~65mg of caffeine, 200~300mg of green tea, 350~400mg of black tea and about 100mg of cocoa. Excessive intake of caffeine is prone to tinnitus, hypercardisia (increased heartbeat and pulse frequency), uneven pulse beat and other symptoms, so be sure to drink coffee in moderation. Second, health and caffeine There is no data showing that caffeine or drinking coffee is harmful to the body. On the contrary, some studies show that caffeine is beneficial to human health. People often ask: How much coffee is excessive? In fact, it all depends on the individual's tolerance and habits. A cup of coffee contains an average of 60 to 90 milligrams of caffeine, while ordinary people can consume nearly 500 to 600 milligrams of caffeine every day without any side effects. Coffee, tea and coca-cola are not addictive. Although many people are used to drinking these drinks for a long time, they just like their taste and refreshing effect, and it is not difficult to quit. Pregnant women have a slow metabolism, so they should drink less coffee. Unlike smoking or drinking, drinking coffee will not have adverse consequences on the development and weight of the fetus. In the United States, a survey of 85,000 nurses in the past ten years found that moderate coffee intake has nothing to do with the incidence of heart disease, nor with various hypertension diseases. There is only one special way to make coffee, which is not good for your health. In Scandinavia, according to tradition, people will boil coffee for several hours to extract more coffee oil from coffee. The coffee brewed in this way contains a lot of cholesterol, which is easy to cause heart disease and cancer. The taste of this coffee is also very different from that of coffee brewed by other methods. Third, does drinking coffee affect sleep? Many people have the experience of being unable to sleep because of high spirits after drinking coffee. This is because there is a conductive substance called adenosine in the human body, which can control nerve activity, leading to slow breathing, weakened mood, reduced gastric acid secretion and diuresis. Caffeine will fake adenosine, which will make the body think that adenosine is acting, make you feel energetic, increase your stomach acid, urinate more frequently, and naturally you can't sleep. It is worth noting that the short-term wakefulness caused by caffeine does not mean that physical strength has really recovered. In addition, everyone has different metabolic rate and sensitivity to caffeine, so some people don't feel that their sleep is affected after drinking coffee. Therefore, having a cup of hot coffee after getting up in the morning can refresh your mind and make you feel more comfortable, but you may lose sleep at night. 2. Will coffee lead to calcium loss? In recent years, people pay more and more attention to the problems of calcium loss and osteoporosis, and also have considerable doubts about coffee. As for the relationship between caffeine intake and osteoporosis, it is still under continuous study. At present, there is no direct evidence that caffeine can cause osteoporosis, but some studies have pointed out that caffeine can increase calcium loss. Therefore, it is suggested that people who love coffee eat more high-calcium foods to supplement calcium, such as preparing cheese slices or cakes with coffee, which can not only supplement calcium, but also make coffee more delicious. Is it right to drink coffee while it is hot? The best drinking temperature of coffee is 85 ~ 88 degrees Celsius. A good cup of coffee, regardless of the temperature, should have the same taste, which is why coffee testers list the whole process of coffee from hot to cold as an evaluation. A cup of good quality coffee will not reduce the flavor after cooling, but also show a better taste than when the temperature is hot. However, due to the instability of coffee itself, most people are encouraged to drink it while it is hot. From one point of view, when a cup of hot coffee is placed in front of you, drinking it while it is hot is the etiquette of coffee. Fourth, who is not suitable for drinking coffee? Patients with cerebral hemangioma are not suitable for drinking coffee, and patients with heart disease should drink coffee without or with low caffeine, because caffeine will accelerate the heart rate and cause cardiac hypoxia. In addition, patients with skin diseases and stomach diseases should drink as little coffee as possible to avoid aggravating their illness due to excessive drinking. Diabetic patients should also avoid drinking coffee with too much polysaccharide, so as not to aggravate the condition. The US Food and Drug Administration (FDA) issued a statement advising pregnant or potential pregnant women to reduce caffeine intake. Because pregnant women metabolize caffeine about twice as fast as non-pregnant women in the middle and late pregnancy, and caffeine will also enter the fetus through the placenta, or enter the baby through breastfeeding. In addition, many studies have failed to prove that moderate caffeine will have adverse effects on the fetus, and there is no medical report prohibiting pregnant women from drinking coffee. Pregnant women and breast-feeding women are still advised to be more cautious about caffeine intake. In short, if you find yourself unwell after drinking coffee, you should stop drinking coffee for a while and then reduce your intake.