1, refreshing: Caffeine in black coffee is a xanthine alkaloid compound and also a central nervous system stimulant, which can temporarily dispel drowsiness, restore energy and make the mind clear.

2, appetizing digestion: caffeine contained in black coffee can stimulate gastrointestinal secretion of gastric acid, thereby promoting intestinal peristalsis, helping digestion, while accelerating gastrointestinal peristalsis, but also conducive to the discharge of feces, to prevent constipation.

3, diuretic swelling: caffeine in sugar-free black coffee can promote renal function, discharge excess sodium ions in the body, increase urination, improve bloating and edema.

Precautions for drinking coffee

Avoid drinking coffee when drinking. Drinking white wine with caffeinated drinks will aggravate the harm of alcohol to human body. Alcohol and caffeine can excite and inhibit the brain, make the brain from extremely excited to extremely inhibited, stimulate blood vessel dilation, accelerate blood circulation, and greatly increase the burden on the heart.

People with calcium deficiency should avoid drinking coffee. Studies by foreign researchers show that drinking two cups of coffee drinks will lose about 15 mg of calcium in the body, so people who drink this drink often should eat more foods rich in calcium, such as meat, bean products, shrimp skin, kelp, laver and fungus.

Refer to Baidu Encyclopedia-Black Coffee, People.com-Diuretic Decomposition of Fat Black Coffee has many benefits to lose weight, but you must find the right time to drink it. People's Daily Online-Coffee can not only refresh people, but also prevent cancer and Alzheimer's disease.