Why do I get tired after lunch?
Last updated September 3, 2026.
The post-lunch dip is a circadian event, not just a food coma: alertness dips in the early afternoon even if you skip lunch. Meals then amplify it, especially large, high-fat, or high-carbohydrate ones, plus rapid blood-sugar swings. Shrink it with a moderate, protein-led lunch, morning daylight, solid sleep, and a 10-minute walk after eating; a short nap works better than willpower if you can take one. Crashing hard daily despite good sleep and reasonable meals, especially with heavy snoring, can point to sleep apnoea, insulin resistance, anemia, or thyroid issues and deserves a GP mention.
What to do
- Keep lunch moderate; lead with protein and vegetables over refined carbs.
- Walk 10 minutes after eating instead of sinking straight into a chair.
- Get morning daylight and a consistent wake time; a strong clock blunts the dip.
- See a GP if the crash is extreme every day, especially with heavy snoring or poor sleep.
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