Drinking black coffee in the morning does not help you lose weight. Although the caffeine in black coffee has the function of making the human body vasoconstriction, can make the body’s metabolism accelerated, which can make the consumption of calories increased, can achieve the effect of accelerated decomposition of fat, but also to promote the body’s excess water quickly out of the body. However, its content is limited, can not play a role in weight loss. Caffeine can excite the visceral sympathetic nerves, promote intestinal peristalsis, black coffee in the morning should pay attention to the following issues. 1. Should not drink black coffee on an empty stomach: freshly ground coffee will stimulate gastric juices, and drinking black coffee on an empty stomach in the morning is likely to lead to discomfort in patients with gastric ulcers and other diseases. 2. Drinking black coffee should pay attention to the right amount: 150ml per cup. The amount of coffee should not be more than 3 cups per day, too much caffeine will make the nerve center overexcited, causing insomnia, anxiety and irritability, so you should never drink coffee in excess, generally speaking, 2-3 cups per day can meet the needs of the day.