Fructose is responsible for making many of the fruits that we love sweet and delicious. If you think you have trouble digesting fructose, we know that it can be difficult to completely avoid it in your diet without cutting out a lot of fruit and vegetables. So why not use the FoodMarble app to check the amount of fructose in all your favourite foods?

What is fructose?

Fructose is a naturally occurring sugar that can often be found in the presence of glucose. When fructose is present in the same amounts as glucose it is readily absorbed by our body, however when there is excess fructose, this is when the problems can occur.

Examples of foods containing fructose

  • Banana – 1 medium ripe banana (112g) is considered high FODMAP
  • Watermelon – 150g of watermelon is considered high FODMAP
  • Apple – 1 medium apple (200g) is considered high FODMAP
  • Mango – half a mango (140g) is considered high FODMAP
  • Pear – 1 medium pear (170g) is considered high FODMAP
Mango smoorthie on white wooden table

Image by Imoflow from Pixabay

How is fructose digested?

The digestion of fructose occurs via sugar transporters in the small intestine. The ability to absorb fructose varies considerably between individuals, this is why it is important to test your unique response. Unabsorbed fructose may draw water into the small intestine. Our body does this to rebalance the environment and reduce the high concentration of fructose.

What are the common symptoms associated with poor digestion of fructose?

In some people, the excess water may result in bloating and diarrhea, but it can also force the undigested food into the colon, where it becomes food for your gut bacteria. However, this produces gases that can lead to many distressing symptoms such as abdominal pain, bloating, constipation, and/or diarrhea.

In those with sensitive guts, even small doses of fructose can result in osmotic diarrhea,
bloating and increased flatulence. This is why it is important to identify your unique tolerance, as this can vary considerably from person to person.

Can I test this myself?

If you suspect that you may have an issue absorbing fructose, the FoodMarble AIRE can help! By conducting a FODMAP Challenge using the Fructose FODMAP sachet, you can quickly observe how your body processes fructose in real-time in a non-invasive manner.

I have outlined below how you can use your FoodMarble AIRE to find out. Hydrogen breath testing with your FoodMarble AIRE is a quick, non-invasive way to assess your tolerance to fructose (and other FODMAPs!). You can purchase sachets of FODMAPs from our website (fructose, sorbitol, lactose and inulin) to consume for the test. The FoodMarble app takes you through the whole test which lasts approximately three hours.

The FoodMarble AIRE Fructose Challenge

By navigating to the “Challenge” section in the FoodMarble app, you can start the Fructose Challenge. You will be provided instructions that will help you to conduct your challenge with ease and confidence.

After taking your initial “baseline” breath test, you will be prompted to mix the fructose powder with water and drink it all down. You will then take breath tests every 15 minutes for the next three hours – you can do this at your desk in work or even in the comfort of your own home at the weekend!

It is possible for you to experience symptoms during the challenge, but since the testing is done in a fasting state, the likelihood is greatly reduced. You’ll be surprised at how differently we all respond to the same things. Be certain to note the onset and alleviation of symptoms, as this is something that will come in handy as you test your favourite foods going forward.

There is a detailed blog on our website by my colleague Claire outlining the Fructose Challenge in detail.

If you have completed a fructose breath test and experienced symptoms, we recommend you repeat the test (when you have no symptoms) using a smaller dose. You could also try a Custom Challenge using a food with a known amount of fructose. Finding your tolerance level is key to maintaining a balanced and healthy diet.

Check out our other blogs about different FODMAPs:

All About Fructans

All About Sorbitol & Mannitol

All About Lactose


Header image by candoyi from Pixabay

Ricky Harrison, MPH

Ricky Harrison, MPH

1 March, 2020 | AIRE, Health

FoodMarble AIRE is the world’s first personal hydrogen breath tester. It is a pocket-sized breath analysis device. It helps people with chronic digestive issues determine the foods that work best with their digestive system. To learn more about FoodMarble, visit or follow us on