Sleepiness and drowsiness after a meal is a normal physiological phenomenon because the gastrointestinal tract breaks down the food after eating, and the carbohydrate and fat content continues to rise, leading to an increase in blood sugar levels in the body, which can inhibit neurons in the brain. A large amount of blood is released into the gastrointestinal tract to help break down and digest the food, which leads to localized transient ischemia in the brain, resulting in drowsiness. In addition to this, the peristaltic work of the gastrointestinal tract also inhibits the local activity of the brain through the neuromodulatory system, thus causing sleepiness, which is a normal physiological phenomenon that can be relieved by taking a break after a meal. However, it may also be caused by diseases, such as diabetes, cardiovascular diseases, etc., which can affect the metabolic function, thus causing similar symptoms.