Not greedy for being late. Eating time of three meals should be sooner rather than later, which is conducive to food digestion and rest after meals, and avoids food accumulation or hypoglycemia. Not greedy for heat. The diet of the elderly should be warm and not hot, because hot food is easy to damage the mouth, esophagus and stomach. If the elderly eat hot food for a long time, they are also prone to stomach cancer and esophageal cancer.