Bananas are different in size and each person’s physical condition is different, so it is impossible to generalize how many bananas are good to eat a day. Under normal circumstances, it is appropriate for a healthy adult to eat 2 bananas a day; if you like to eat them, it is okay to eat 1 more occasionally if your body allows it, but be careful to eat them separately and not 3 at a time. If you are a child or an elderly person, you can eat 1-2 bananas a day. People with poor gastrointestinal function, such as those with frequent diarrhea and stomach pain, should eat 1 banana a day or not. Bananas are rich in protein, glucose, fiber, vitamins, carotenoids, potassium, iron and phosphorus, etc. Therefore, eating them in moderation for healthy people can help promote gastrointestinal peristalsis and speed up bowel movement, especially for constipation. The potassium ions in bananas are also beneficial to patients with high blood pressure and coronary heart disease. In addition, bananas also contain tryptophan, which can promote the brain to produce 5-hydroxytryptamine, which can be converted into melatonin, with a sedative effect, can relieve nervousness and anxiety, and also the role of sleep aid, but it should be noted that people who are allergic to bananas should avoid eating bananas, so as not to induce or aggravate allergic symptoms. Diabetic patients, do not eat bananas or eat less, so as not to lead to increased blood sugar. In addition, attention should be paid to avoid eating bananas on an empty stomach or in excess to avoid stimulating the gastrointestinal tract and increasing the burden on the digestive tract, which may cause indigestion, bloating, abdominal pain, diarrhea and other uncomfortable symptoms.