Drinking coffee on an empty stomach is a bad idea; here’s why

Few rituals are as universally cherished as that first cup of coffee in the morning. For some, it’s a moment of stillness before the day begins; for others, it’s a social prelude to the workday, shared over clinking cups and quick exchanges. While green tea has made its case as a worthy alternative, the allure of a perfectly brewed arabica remains unmatched.

But here’s where the ritual gets tricky—drinking coffee on an empty stomach might not be the best idea. While it jolts you awake, it can also trigger a cascade of side effects, from digestive discomfort to heightened cortisol levels (read: unnecessary stress before you’ve even opened your inbox). In a world obsessed with wellness, it’s worth reconsidering whether your morning caffeine fix needs a supporting act—a bite of something solid to keep your system in check.

So, before you reach for that espresso shot first thing, you might want to rethink the order of your morning routine. Your stomach will thank you.

What happens when you drink coffee on an empty stomach?

Acidity and poor digestion

Drinking coffee on an empty stomach can increase gastric acidity. Coffee stimulates the production of hydrochloric acid in the stomach, which, if not balanced by some food, can irritate the gastric mucous membranes. This can lead to a burning sensation, gastroesophageal reflux (when stomach acid flows back up the tube that connects the mouth and the stomach), and gastritis – especially in those who are already prone to stomach problems. Acid can erode the gastric mucosa (the slippery protective layer that lines the inner surface of the stomach) more easily when it is not protected by food, increasing the risk of inflammation.

Cortisol spike and hormonal stress

Beyond its rich aroma and energising kick, coffee has a direct impact on our hormonal system—specifically, cortisol, the so-called stress hormone. Naturally, cortisol levels peak in the morning to help us wake up, but drinking coffee on an empty stomach can push those levels even higher, sending the body into a state of unnecessary stress.

The result? A jittery, anxious feeling that’s less “calmly caffeinated” and more “edge-of-a-burnout.” Over time, excess cortisol can throw your metabolism off balance, disrupt sleep patterns, and leave you feeling more wired than wonderful. In short, that first cup—when consumed without a buffer—might be doing more harm than good.