Is coffee low FODMAP? Espresso, milk and caffeine explained

Short answer: yes, plain coffee is low FODMAP at a normal cup.

Monash University has tested espresso, brewed coffee and instant coffee, and lists all three as low FODMAP at a typical serving. So the coffee itself is rarely the FODMAP question.

The questions start with what goes into the cup, and with what coffee does to the gut that has nothing to do with FODMAPs.

Black coffee: espresso, filter and instant

Coffee beans are roasted seeds. Once brewed, the drink holds very little carbohydrate, and carbohydrates are what FODMAPs are.

That is why black espresso, filter coffee and instant coffee all have a low FODMAP serving. Decaffeinated versions have the same FODMAP status. For the exact serving sizes Monash has tested, check the Monash University FODMAP app, because figures can change when foods are retested.

The milk matters more than the coffee

In a latte or a flat white, most of the cup is milk. So the milk often decides the FODMAP profile of the drink.

• Regular cow's milk contains lactose. A splash in an espresso is a small amount. A large latte is a much bigger one. Our milk aisle guide explains how serving size changes things.
• Lactose-free milk has a low FODMAP rating. The lactase enzyme breaks the lactose down before the milk reaches you. Our article on lactose-free vs low FODMAP explains how.
• Soy milk depends on how it is made. Soy milk made from soy protein can be low FODMAP. Soy milk made from whole soybeans is higher in GOS.
• Oat milk is portion-dependent, and recipes vary between brands.
• Almond milk has a low FODMAP serving in Monash testing.

With any plant milk, read the ingredient list. Some brands add inulin or chicory root fibre, which are sources of fructans.

Syrups, sweeteners and coffee mixes

Sugar has a low FODMAP rating, so a spoon of sugar in your coffee is not a FODMAP concern. Other sweet additions can be:

• Honey and agave carry excess fructose at typical servings.
• Sugar-free syrups are sometimes sweetened with polyols such as sorbitol or xylitol.
• "3 in 1" sachets and flavoured instant mixes can contain milk powder, whey, inulin or other ingredients that change the profile.
• Creamers vary a lot. Some are mostly oil and glucose syrup. Others contain milk solids or added fibre.

Our guide to low FODMAP sweeteners sorts the common names you find on a label.

Chicory and coffee substitutes

Some coffee alternatives and some ground coffee blends contain roasted chicory root. Chicory root is rich in inulin, a type of fructan. So a chicory drink has a very different FODMAP profile from coffee, even if it looks and tastes similar. Check the label on any "coffee alternative" or blend. The drink aisle guide lists other label terms to look for on this shelf.

Coffee can affect the gut without FODMAPs

This is the part that surprises many people.

Coffee stimulates the colon. According to a Monash University review of the research, coffee led to an urge to open the bowels in nearly one third of healthy people in one study. Decaffeinated coffee also increased colon activity, but less than regular coffee. So caffeine is part of the effect, but not all of it.

Many people with IBS report coffee as a trigger. And the same Monash article notes that there is little research showing that cutting caffeine improves IBS symptoms in general. Tolerance is individual.

This has a practical side. If a strong coffee is followed by urgency or cramping, that is not proof that FODMAPs are to blame. During the elimination phase, it can help to note your coffee habits in your symptom diary. Then you and your dietitian can tell a FODMAP reaction from a coffee reaction.

So, can you keep your morning coffee?

Coffee can have a place on the low FODMAP diet. The coffee itself is low FODMAP. The milk and the extras are where the FODMAPs tend to be. How your gut responds to caffeine is a separate question, and the answer differs from person to person.

If coffee seems to bother you, a FODMAP-trained dietitian can help you look at the whole picture, including how much you drink and when.

Let Belly Buddy check the milk and the mix

The coffee is simple. The carton of oat milk or the jar of flavoured instant coffee is where a label can get long. Scan the ingredient list with Belly Buddy to get a clearer view of its FODMAP profile. Belly Buddy flags declared sources of lactose, inulin, chicory, polyols and other FODMAPs when they appear in the ingredient list. It cannot tell you how your gut responds to caffeine.

Our rating method explains how Belly Buddy analyses ingredients and reaches a verdict.

Belly Buddy is not affiliated with or endorsed by Monash University. Our FODMAP information is informed by publicly available scientific sources, including research from Monash University.