December 27, 2022

The Big Lunch and “Afternoon Sleeping Sickness”

After-meal drowsiness may be affected by meal timing and regularity, meal quantity, and meal composition—not just your individual characteristics.

Peter N. Landless & Zeno L. Charles-Marcel

Q: Why do I get so sleepy and tired after eating lunch, and what can I do about it?

A: You’re not alone! Your condition is shared by many and has been found in worms, snakes, rodents and other mammals, and even insects. This common occurrence is known medically as “postprandial sleepiness,” “the post-lunch dip,” and colloquially as “food coma.” 

It’s usually no cause for concern except if it interferes with your work, school, or social life—especially when your after-meal activity requires high alertness, such as driving a car or operating potentially dangerous equipment. Excessive sleepiness may also be related to underlying health problems or sleep disorders, so please see your doctor to discuss your unique situation. 

Here are some ideas to combat afternoon sleepiness that come from ongoing research: 

Food coma is a circadian effect worsened by a poor night’s sleep. It’s an afternoon phenomenon since it usually occurs about 30 minutes after eating lunch. Some research points to post-meal changes in blood circulation. Blood flow to the intestines dramatically increases after we eat, and this provokes a corresponding decrease in blood flow to the brain, which could trigger feelings of fatigue and sleepiness. This may be particularly at play when we skip breakfast, have a large lunch, and engage in monotonous tasks after eating. 

Other research indicates that blood sugar and insulin fluctuations after meals may stimulate after-meal drowsiness. Diets heavy in processed meat, fast food, and soft drinks have been shown to be associated with more daytime sleepiness in truck drivers, probably because of the combination of high animal fat and processed carbohydrates along with high salt. Unhealthful diets have a disruptive effect on day-to-day body rhythms and are linked to post-meal fatigue through elevated cytokines such as interleukin-1 (IL-1), a marker of inflammation. 

“Afternoon sleeping sickness” appears to be a “normal” response to certain kinds of meals, certain mealtime situations, how much food we eat, and our individual circumstances and inherited and cultivated tendencies. Overarching advice includes eating smaller, healthful vegetable-centric meals on a regular schedule and strolling after eating. A walk after eating has multiple beneficial effects on our digestion, metabolism, and weight management, so it’s a good habit to have. If after-meal drowsiness significantly interferes with routine living or is accompanied by other symptoms, physician consultation is highly recommended. And remember: “Whether you eat or drink, or whatever you do, do all to the glory of God” (1 Cor. 10:31). 

Tips for Food Coma 

  • Have a good breakfast.
  • Eat smaller meals on schedule.
  • Eat vegetables and natural plant fats.
  • Take a 10– to 15-minute after-meal stroll. 

If drowsy: 

  • Turn up the lights.
  • Chew sugarless gum.
  • Listen to your favorite upbeat music.
  • Drink (and wash your face with) cold water.