Expert reveals little-known reason you’re always exhausted at 3pm

A doctor has revealed why the afternoon slump happens – and ways to avoid it.

As the clock strikes three in offices everywhere, a familiar feeling might wash over you.

Your eyelids might feel heavier, thoughts become clouded, and you feel as though you could quite literally fall asleep at your desk.

It’s well known as the 3pm slump or “sweet treat o’clock” – for those who reach for a coffee or snack to power them through the afternoon.

But while it might be a universal struggle, you might not understand exactly why it happens, and therefore don’t know the right ways to combat it.

Bad news for caffeine fiends everywhere – the answer isn’t always a double shot oat latte.

A doctor has revealed the reason you're always tired at 3pm. Picture: TikTok

Why does the 3pm slump happen?

According to Dr Zac, a medical practitioner specialising in preventive health and wellness, there’s a solid scientific explanation behind this phenomenon.

“Your body runs on a natural circadian rhythm — an internal clock that regulates sleep, energy, and other bodily functions,” he tells news.com.au.

“Around 2–3 pm, this rhythm naturally dips, making you feel sleepy, less alert, and a bit sluggish.”

This dip in energy often aligns with the post-lunch crash – when your body diverts blood to the stomach for digestion, leaving less available for your brain.

If you’ve had a large meal, this can worsen the feeling.

It is partly due to your circadian rhythm. Picture: TikTok

How to avoid and power through the slump

Getting adequate sleep is crucial, according to Dr Zac, and he suggests people aim for seven to nine hours each night.

“Sleep is when your body restores energy, repairs cells, and consolidates memories,” he notes.

To make the most of it, he suggests maintaining a regular sleep schedule, avoiding screens before bed, and keeping your sleep environment dark and cool.

Food choices also directly impact your energy levels throughout the day.

A carb-heavy lunch can leave you feeling sluggish, as it may cause blood sugar levels to spike and crash.

Dr Zac recommends opting for meals that balance protein, healthy fats, and complex carbohydrates for steady energy.

Healthy snacks like nuts, yoghurt, or fruit with protein (think apple with almond butter) can help prevent energy dips.

Additional dietary considerations

“Heavy, fatty foods are known to slow down digestion because fats require more time to be broken down and absorbed,” he explains.

“This delayed gastric emptying can divert blood to the digestive process, intensifying that post-lunch lethargy.”

He cites research that indicates that high‐fat meals significantly slow digestion compared to lighter options.

In comparison, incorporating raw, crunchy foods into your daytime meals can help you stay alert.

Chewing these foods not only assists in mechanical digestion by increasing saliva production but also supports a healthy gut microbiome – your beneficial gut bacteria – thrive on the natural fibres and enzymes found in unprocessed foods.

This can contribute to sustained energy and mental clarity throughout the day.

Your food can also play a part in why you feel tired. Picture: TikTok

In addition to sleep and dietary factors, water also plays an essential role in combating the 3pm scaries.

“Even mild dehydration can cause fatigue,” he warns.

“Ensure you’re drinking enough water throughout the day, around two to three litres, depending on activity levels.”

And no, coffee doesn’t count as hydration!

Taking a quick break to stretch or go for a brisk walk can also do wonders for your energy.

Movement increases blood flow, boosts endorphins, and can help clear your mind, making it easier to power through that afternoon dip.

Lastly, Dr Zac recommends getting some natural light soon after waking.

This helps regulate your circadian rhythm by suppressing melatonin production in the pineal gland, which is a natural cue that tells your body it’s time to be alert and active.

Dr Zac suggests swapping your afternoon coffee for a matcha or green tea. Picture: TikTok

Let’s talk coffee

As hinted, caffeine can indeed contribute to the afternoon slump.

While it provides a short-term boost, it may interfere with your sleep if consumed too late, making you more likely to feel tired the next day.

“Once its effects wear off, you might feel even more fatigued,” Dr Zac says. “So if you’re craving an afternoon pick-me-up, consider green tea or matcha, which offer a more gradual energy release than coffee.”

Could the 3pm slump be a sign of something else?

If your afternoon slump feels persistent or severe, it could signal an underlying issue like hormonal imbalances, blood sugar dysregulation or chronic fatigue.

If you’re experiencing other symptoms (like unexplained weight changes, excessive thirst, or persistent brain fog), it’s important to consult your GP.

Originally published as Expert reveals little-known reason you’re always exhausted at 3pm