Sudden increase in meal size and body weakness may be caused by neurological polyphagia, hyperthyroidism, gastrinoma, and so on. 1. Neurogenic polyphagia: also known as bulimia, the patient will experience recurrent overeating, but may be due to mental reasons leading to physical weakness, mood is not high. 2. Hyperthyroidism: that is, hyperthyroidism, mainly due to increased secretion of thyroxine, resulting in accelerated metabolism caused by the patient will often appear to increase the amount of food, weight loss and other phenomena, and accompanied by fatigue, palpitations (heartbeat accelerated, often accompanied by panic) and other symptoms. 3. Gastrinoma: it is a kind of relatively common neuroendocrine tumor, with the gradual growth of the tumor, it will stimulate the secretion of gastric hormones and gastric acid, resulting in increased food intake, but due to the fact that the tumor is a consumptive disease, it will lead to body weakness and weight loss. It is better to consult the doctor in time for sudden increase in meal quantity and find out the cause and then target treatment to avoid delaying the treatment.