Coffee on an empty stomach: who should avoid it and who need not

Some people have drunk a glass of black coffee before breakfast for thirty years and been perfectly fine. Others drink half a glass on an empty stomach and feel hollow, shaky and faintly nauseated all morning. The same coffee.

The difference is not who is tougher. It comes down to a few specific things.

What coffee does to an empty stomach

Two things happen at once:

It stimulates stomach acid

Coffee — caffeinated and decaffeinated alike — stimulates acid production. With food in the stomach, that acid has something to do. On an empty stomach it has nothing to digest, and for anyone with a sensitive lining that is felt as hollowness or burning.

Caffeine enters the blood faster

With no food to slow it down, caffeine is absorbed more quickly and reaches a higher peak. This is why the same glass leaves you with a fast heartbeat and slightly shaky hands when taken on an empty stomach, and does not after a meal.

Put those two together and you have explained almost every case.

Who should avoid it

Four groups run into it most clearly:

• People with reflux. Coffee relaxes the lower oesophageal sphincter, making reflux more likely — and more so on an empty stomach.
• People with gastritis or an ulcer. This group should ask a doctor rather than experiment.
• People sensitive to caffeine. Tolerance varies enormously between individuals, largely through differences in how fast it is metabolised. A slow metaboliser can get shaky hands from a single glass.
• People who are anxious or short of sleep. Caffeine amplifies both. Hungry plus underslept plus coffee is the least comfortable combination there is.

Who need not worry

Most healthy people drink coffee on an empty stomach without any problem, and there is no reason to abandon the habit if it suits you. The body does adapt to regular coffee, and people who drink it daily generally react less than occasional drinkers.

Worth saying, to head off a common misconception: “coffee on an empty stomach damages your stomach” is not true for everybody. It is true for some groups.

Four adjustments, easiest first

1. Eat a little something first

Not a whole meal. A small loaf, a handful of nuts, a banana — enough to give the acid something to work on and slow the caffeine down. The simplest and most effective step.

2. Take it with milk rather than black

Milk — dairy or plant — noticeably softens the hollow feeling, being both food and dilution. People who struggle with black coffee in the morning are often fine with milk coffee.

3. Choose a darker roast

Counter-intuitive but sound: the longer the roast, the more the acids in the bean break down. Vietnamese-style dark roast is lower in acid than a light roast with fruity acidity. If you are uncomfortable with specialty coffee but fine with phin, this is why.

4. Make it weaker, or drink less

Obvious, but few people test it systematically. Halve the quantity for a week and see whether anything changes, before concluding that coffee does not agree with you.

What about tea?

Tea contains caffeine too, but less, and it is absorbed more slowly, partly because of the tannins. So for sensitive people, tea on an empty stomach is usually easier than coffee.

Lemon tea adds acidity of its own, so anyone with reflux should still eat something first.

At the shops

Early in the morning, if you have not eaten and want a drink, Nut Milk Coffee at 45,000d is gentler than Black Coffee at 35,000d — the nut milk softens the hollow feeling. Gentler still: Jasmine Lemon Tea at 36,000d.

And the tidiest answer is still to eat first: a Bơ Đường at 28,000d is small, lightly sweet and quick, enough to line the stomach before the coffee. The five shops are open 24 hours, so it is available whenever you want it.

38 Lê Thị Riêng, 15B Nguyễn Thị Minh Khai, 2B Trần Hưng Đạo and 148B Đề Thám in District 1, and 210 Bùi Văn Ba in District 7. Call 0923.183.183; orders from 500,000d within 5km are delivered free.

This is general information about eating habits, not medical advice. Anyone with a stomach condition or persistent symptoms should see a doctor.

Quick questions

Does coffee on an empty stomach damage your stomach?

Not for everybody. Coffee stimulates acid production, and on an empty stomach that acid has nothing to digest — which is felt as hollowness by anyone with a sensitive lining. Most healthy people have no problem.

Why does the same glass make my hands shake when I am hungry?

With no food to slow it, caffeine is absorbed faster and peaks higher in the blood. After a meal the same glass feels much milder.

Who should avoid it?

People with reflux, gastritis or an ulcer, those sensitive to caffeine, and anyone short of sleep or anxious — caffeine amplifies both of those.

Is milk coffee gentler than black?

For most people, yes. Milk is both food and dilution, so it noticeably softens the hollow feeling. Plant milk does the same.

Dark or light roast for a sensitive stomach?

Dark, because the longer roast breaks down more of the acid. If you struggle with a light fruity roast but are fine with phin coffee, that is the reason.

Is tea easier on an empty stomach?

Usually, since it has less caffeine and it is absorbed more slowly. But lemon tea adds acidity of its own, so anyone with reflux should still eat something first.