Tomato and egg soup can be eaten overnight. But it is best not to eat, in the fried dishes, a lot of uneaten stored, especially some high protein (eggs are high protein items) high fat leftovers, it is more than enough to eat. Harmful bacteria in the air will attach to the leftovers within 2 hours and begin to reproduce, and we all know that protein and fat in the role of bacteria, most of which will produce harmful substances, such as hydrogen sulfide, amines, phenols, etc., which are harmful to the human body. It is an indisputable fact that eating leftovers for a long time can easily cause cancer. So it is said that overnight food can not be eaten, when cooking, the best way is to measure the amount of food, and not to damage the health.