Are tomatoes low FODMAP?

3 minute read

Let’s start by defining what ‘low FODMAP’ is.

There may not be as much familiarity with the term as In the UK it is still relatively unheard of. It is a dietary therapy, which was founded in Australia at Monash University and then developed further at King’s College University, London.

‘FODMAP’ stands for Fermentable Oligo-, Di-, Mono-saccharides And Polyols (table 1).

Essentially these are sugars/fibres that ferment in the large intestine.

A Low FODMAP diet is used mainly for Irritable Bowel Syndrome (IBS) and sometimes Inflammatory Bowel Diseases.

You remove high FODMAP foods and focus on only consuming low FODMAP foods (see table 2) for a short monitored period of time (4-6 weeks). Your symptoms should be tested by a qualified professional as this is a very restrictive diet and needs to be followed properly to see results.

Once intolerances are identified and symptoms are improved (if not gone all together!), you work long term on reintroducing foods and reverting to a normal diet, only avoiding foods that cause you problems.

So, are tomatoes low FODMAP?

YES! (according to MONASH University app)

The fibre in tomatoes doesn’t ‘ferment’ in the gut and while tomatoes contain fructose, it is not in ‘excess’. It is fructose in excess of glucose that causes a problem for some people. (Note. excessive amounts of anything will cause stomach upset, but a regular large portion of tomatoes will be fine)

So, what’s the deal – a lot of the foods on the ‘avoid’ list are healthy?!

Firstly, this isn’t a weight loss diet. It is not distinguishing ‘good’ and ‘bad’ foods. Rather, it involves categorising foods based on their chemical make-up and assessing what it is within that food that a person could be intolerant to.

“This isn’t a weight loss diet.”

Let’s take lactose for example; the sugar in dairy. It may just be that your body has reduced its production of the enzyme ‘lactase’ which breaks down lactose in the small intestine. This means the lactose molecules travel further to the large intestine before being broken down by your gut bacteria instead. This means that it ferments and causes gas. However, it is more than likely that you will be able to consume small amounts of lactose (12g - approx. 250ml milk) without any problems.

THIS IS A GOOD THING!

To confuse things further, our healthy gut bacteria, like and thrive on the fibre found in these fermentable foods and confer a health benefit to the host (person). But, for some people it causes more discomfort than others. Researchers still aren’t sure exactly why, other than it seems people with IBS have more sensitivity in their gut as the fermentation creates gas that can cause distension, pain, gas etc.

It is complex, and highly individual, but we do also know that symptoms can actually be caused or worsened by stress.

A lot of the foods found in our Gut Health Boxes may contain high FODMAP, as mentioned above, but they are typically beneficial for good gut bacteria, helping them grow and kill off ‘bad’ bacteria. If you notice any changes such as more flatulence, bloating, pain or change in bowel movement it may be that you can’t tolerate a particular FODMAP (there are many), so you may need to find a specialist to help you navigate your intolerance, rather than simply cutting these foods out!

Words by Hannah Norris MSc ANutr. IG: @hanutrition

Table 1. FODMAP definitions from MONASH University. (GOS: galacto-oligosaccharides)

Table 2. Examples of low/high FODMAP foods.