Why you feel tired after lunch? Foods that drain energy

Ever found yourself silently fighting off sleep after a heavy Sunday lunch? Or yawning your way through the drive home after dinner with friends, wondering if something’s wrong with you? Well, the good news is that nothing is wrong with you, but the bad news is that you can’t really fix it.

There’s a name for that sleepy slump: postprandial somnolence.

The science behind it

Our body is already primed for a slight energy dip in the early afternoon, thanks to the circadian rhythm, the internal clock that controls when we feel alert and when we feel tired. Add in your sleep drive (which builds the longer you're awake), and your brain is halfway to shutting down already.

On top of that, eating triggers chemical changes. Meals can increase serotonin and melatonin, hormones that help you relax and prepare for sleep.

Your body also releases cytokines after eating, especially after calorie-dense meals. These immune system proteins have been linked to fatigue and inflammation, both of which slow you down.But here’s the thing: what you eat also affects this post-meal nap.

The foods most likely to drain your energy

You might think any full meal would do it, but some foods are far more likely to send you spiraling into sluggishness. Here’s what to watch for:

Refined carbs and sugars

White bread, white rice, pasta, pastries, soda, these cause your blood sugar to spike, and then when they crash, they take your energy with it.

That sugar rollercoaster is why a sweet dessert or overly processed lunch leaves you drained instead of fueled.

High-fat fried foods

Think burgers, fries, or creamy sauces. These meals feel heavier in your stomach and take longer to digest, diverting more blood to your gut and away from your brain. This results in a major slowdown in alertness and focus.

Large portion sizes

It’s not just what you eat, but how much. Overeating can lead to a more intense drop in energy because your body is working overtime to digest.

That’s why even “healthy” foods in giant portions can leave you feeling like you’ve hit a wall.

Turkey and heavy proteins + carbs

It’s not just tryptophan. That post-Thanksgiving crash? It’s the combination of carbs and protein that increases serotonin, which contributes to drowsiness.

What to eat instead (if you want to stay awake)

Go for balanced meals with complex carbs, lean proteins, and healthy fats, like grilled chicken with quinoa and greens, or lentils with veggies. Add fiber, cut back on sugar, and consider swapping fried sides for something lighter. Even something as simple as drinking water instead of a sugary drink can help.