The Right Time to Drink Coffee for a Healthy Metabolism

a woman drinking coffee and using laptop

Coffee is one of the most popular beverages worldwide, and that too, for some solid reasons. Not just it smells good and tastes great; it contains a vital stimulant called caffeine too. According to research, where caffeine can perk you up, it can negatively affect your metabolism.

According to a study published in the British Journal of Nutrition, having coffee before breakfast the day after a bad night’s sleep can acutely impair metabolism.

In this study, the participants who drank black coffee after a bad night’s sleep and followed that with a sugary drink (consider it a substitute for breakfast) had impaired blood sugar control – a symptom of metabolic dysfunction.

Researchers hired 29 healthy men and women to determine how disrupted night’s sleep and morning coffee influence metabolic function. The summary of this study is as follows:

  • Participants had approximately eight hours of sleep and then woke up to a sugary drink in the morning.
  • Participants experienced a bad sleep where researchers woke them every hour for five minutes by automated text prompts. And then, upon waking up, they were given a sugary drink.
  • Participants experienced the same disrupted night’s sleep but were first given a cup of strong black coffee (having 300mg of caffeine) 30 minutes prior to consuming the sugary drink.

The study’s result was that consuming strong black coffee right after waking up from broken sleep increased the blood glucose response to breakfast (sugary drink) around 50%. Although this shift doesn’t necessarily put one at risk for diabetes or other metabolic disorders, scientists say that it might influence health if the spike occurs daily.

Coffee – A Proven Health Promoter

pouring coffee in a white ceramic mug

Where caffeine can affect badly if consumed at the wrong times, it can work magic in lifting your energy levels and moods if taken at the right times. Wondering how coffee can help this much? The reason is the excess of antioxidants and vitamins present in it. Following are the most important components in coffee that can aid in improving our health:

  • 2-Ethylphenol

This chemical provides coffee that particular aroma and is also responsible for keeping us alert and active after consuming coffee.

  • Trigonelline

Trigonelline is a form of vitamin B3 known for fighting cavities that cause tooth decaying bacteria.

  • 3,5 Dicaffeoylquinic Acid

This antioxidant present in coffee doesn’t only offer protection from neuron damage but also helps keep neurons healthy and active.

  • Niacin

Niacin is vitamin B3 that rejuvenates cells and prevents dementia, diarrhea, and skin problems.

The Science behind the Best Time to Drink Coffee

Okay, you might know two or three (or maybe more) health benefits of coffee, but did you know that there is a “best time” for drinking coffee? I can understand that ‘every time is coffee time’ for a coffee lover, but science has much more to add.

To better understand the right time to drink coffee, let us first learn about the natural clock in the human body and how it works.

Circadian Rhythm and Cortisol Levels

Our brain has a pretty complex structure, and it controls many intricate activities of our body. One of our brain parts, the Suprachiasmatic nucleus (SCN), is known for producing and releasing the stress hormone (cortisol). This is the super hormone that is also responsible for our alertness and sleep patterns.

In addition to that, cortisol is responsible for running and maintaining the 24-hour pattern that decides basic body functionalities, such as when to eat, sleep, and perform other metabolic activities.

This cycle varies based on sleeping and eating habits and other factors. I have tried to explain it in a better way below.

If you sleep at 10-ish PM and wake up at 6 or 6:30 AM, the cortisol levels in your body are at the peak at:

  • 8 to 9 AM
  • 12 Noon to 1 PM
  • 5:30 to 6:30 PM

Naturally, our body is active at this time, even without consuming caffeine. If you are a late owl (waking up at 10 or 11 AM), then the cortisol’s peak times will be the above timings with three hours added to each of them.

On the other hand, for early birds (who wake up before 4 AM), this is the other way around – means you have to minus three hours from each of them.

So, What is the Best Time to Drink Coffee?

Now, I hope that you are aware of the science behind drinking coffee at different times. Therefore, according to all these studies and experiments, we can say that 9.30 AM to 11.30 AM is the best time to drink coffee for a healthy metabolism. During this two hour window, you can safely drink up to 8oz. of coffee.

When Not to Drink Coffee?

a person reading newspaper with coffee on the table

According to chronopharmacology, one should never drink coffee when their cortisol levels are at their peak. The reason is that your body’s cortisol levels are already at their peak, and after consuming caffeine, they will increase beyond tolerance. According to a study published in the Journal of Clinical Endocrinology & Metabolism:

  • Never drink coffee with your breakfast at 8 AM – 9.30 AM.
  • Never drink coffee with your lunch from 12 Noon to 1.30 PM.
  • Never drink coffee after 4 PM because coffee stays in your stomach for about 12 hours, and it might affect sleep patterns at night.

How Much Coffee is Safe?


According to a study, healthy individuals can consume up to 400mg of caffeine daily (about 4 cups). On the other hand, it is 300mg of caffeine for pregnant and nursing women. Other common sources of caffeine include soft drinks, tea, energy drinks, and dark chocolate.