A sudden increase in meal size may be a sign of hyperthyroidism, diabetes, or may be related to increased physiologic consumption. 1. Hyperthyroidism: Hyperthyroidism can lead to hypermetabolism and a sudden increase in meal size, which may be accompanied by other symptoms such as panic, lethargy and irritability. 2. Diabetes mellitus: diabetes mellitus patients can’t utilize sugar well and lack of energy, which can also lead to a sudden increase in the amount of food, and may be accompanied by symptoms such as wasting, drinking and urinating. 3. Physiological consumption increase: such as the recent increase in the amount of exercise or engaged in heavy labor, resulting in increased physiological consumption of the body, there will also be a sudden increase in meal size, this is a normal physiological phenomenon. There are many reasons for sudden increase in meal size, not only including the above, if accompanied by other abnormal manifestations, it is recommended to actively seek medical advice, under the guidance of a professional physician to clarify the specific cause of the disease.