Only sleepy after meals can not be diagnosed as diabetes, normal people can also be sleepy after meals, because after meals, blood into the stomach more work, the brain temporary ischemia. But diabetic patients are more likely to be sleepy, diabetic patients after meals, blood sugar rises rapidly, easy to appear insulin resistance. Normal people after meals carbohydrates into the body quickly into glucose, insulin receptors in time to break down carbohydrates into sugar, into the cell for utilization. Once the intake of carbohydrates too much, the body’s blood sugar increases rapidly, a large amount of blood sugar accumulation in the body, prompting the pancreas to increase the secretion of insulin, and this vicious circle, so that the pancreas burden is overly aggravated, and over time, resulting in insulin resistance, which occurs in hyperinsulinemia, which can lead to diabetes mellitus.