Because bananas contain more magnesium, eating on an empty stomach will suddenly increase the magnesium in the human body, destroy the balance of magnesium and calcium in the blood, have an inhibitory effect on the cardiovascular system, and are not good for the stomach and intestines, which is not conducive to health.

note:

Foods that can't be eaten on an empty stomach include bananas, oranges, pineapples, hawthorn and persimmons. Some ingredients contained in these fruits will promote the secretion of gastric acid, or will destroy a certain balance of the human body.

And milk. If you drink protein on an empty stomach, it will not be absorbed by the human body, resulting in a large loss of nutrition.