Why Am I So Sleepy After Eating a Big Meal?

If you often feel tired after eating a big meal, you’re not on your own. Post-meal fatigue is a common experience for many. But why does it exist? Why do people feel tired after a lot of food in one sitting?

There are a few different causes of post-meal tiredness. The severity of your tiredness might vary depending on when you’ve eaten, the volume of food you’ve eaten, and the types of foods.

Certain types of food can increase the levels of an amino acid in your body called tryptophan. In particular, carbohydrates and proteins contain a lot of tryptophan, a precursor to serotonin. Since serotonin helps to regulate your sleep-wake cycle, your mood and your digestion, you can start to feel sleepy when you eat high-tryptophan foods.

Eating large amounts of simple sugars in one go can cause a significant spike in your blood sugar levels. After an hour or two, your blood glucose can rapidly decrease, leaving you feeling tired and sluggish.

Additional factors that can make you feel sleepy after a big meal include poor sleep, lack of movement, and drinking a lot of alcohol.