Postprandial Somnolence

Postprandial somnolence (often called a “food coma”) is the feeling of drowsiness, mental fogginess, or reduced alertness that occurs after eating, especially after a large or heavy meal.

It is thought to result from a combination of factors, including activation of the parasympathetic (“rest and digest”) nervous system, shifts in blood flow to the gut, and changes in hormones and neurotransmitters (like insulin, glucose, serotonin, and orexin) that influence alertness and sleep.​

Large, high‑carbohydrate, or high‑fat meals are more likely to trigger it, but it can also be influenced by meal timing, sleep quality, and underlying conditions like insulin resistance or chronic fatigue.