Eating watermelon on an empty stomach can cause damage to the spleen and stomach, and even induce an attack of gastroenteritis. Watermelon has the effect of eliminating heat and diuretic, but it should not be eaten on an empty stomach. Because watermelon is a cold food, which contains a lot of water. Eating watermelon on an empty stomach will lead to dilution of gastric juices in the stomach, which will not only lead to loss of appetite, but will even affect the peristalsis of the intestines and cause indigestion. As watermelon is too cold, it can irritate the digestive system and cause inflammation when it enters the digestive system. It also leads to contraction and spasm of the digestive system, triggering the onset of acute gastroenteritis. Especially for those who have a cold spleen and stomach, eating watermelon on an empty stomach can aggravate the symptoms of a cold spleen and stomach, which can manifest as abdominal pain and diarrhea. Although watermelon is rich in fructose, but eaten on an empty stomach is not conducive to the conversion of fructose into glucose, some people will be induced by hypoglycemia.