You can eat watermelon when you have a cold, but you should not overeat. Common cold is a self-limiting disease, mostly caused by viral infections. Symptoms are mainly characterized by runny nose, sneezing and coughing. During the cold period, you should pay attention to proper rest, fever, serious condition or old and frail patients should rest in bed, quit smoking, drink more water, eat a light diet, maintain nasal, pharyngeal and oral hygiene. Moderate intake of fresh fruits and vegetables is helpful for the recovery of the body. Watermelon is a kind of water rich in many kinds of vitamins, water, appropriate eating can play a refreshing thirst quenching, replenish the role of energy. But for cold patients, gastrointestinal function is weak, should not eat frozen or too much watermelon. For more information about disease diet, it is recommended to consult a nutritionist in a regular hospital.