The low-FODMAP diet

We looked at the research behind the eating plan to see if it can really provide relief to irritable bowel syndrome (IBS) sufferers. Plus we conducted a taste-test of specially formulated products.

Group of low-FODMAP products

Heard the hype about the “low-FODMAP” diet?

Among the products on shop shelves is “FODMAP friendly” Vogels Café-style Almond and Ancient Grains muesli ($7.69), which promises to be “the optimal blend for gentle digestion”.

You can also find Fodmapped For You Red Wine and Italian Herbs Pasta Sauce. At $6.29, it’s nearly double the price of other sauce brands. The product bears a “FODMAP-Friendly approved food product” logo, and on the back claims it’s “been tested to be low in FODMAPs per serve when cooked and served as instructed”.

Manufacturers base the marketing of these products on a growing body of research suggesting IBS sufferers can relieve their symptoms by reducing their consumption of a group of carbohydrates called “FODMAPs”. The acronym stands for “fermentable oligosaccharides, disaccharides, monosaccharides and polyols”.

They’re found in foods ranging from fruits, vegetables and nuts to lactose-containing dairy products. Many specialty products, including the Fodmapped For You range, promote themselves as containing “no onion or garlic” (foods particularly high in FODMAPs).

The human gut has trouble absorbing these types of carbs. However, it’s a different story for the bacteria living in our gut – which relish these nutrients, but produce gases such as hydrogen and methane as they consume them. FODMAPs also cause our intestines to retain water. Both these things can leave you bloated.

This can happen to anyone after a FODMAP-rich meal, but some scientists believe those with IBS are more sensitive to the effects than others. IBS affects roughly 1 in 7 New Zealanders.

The research

To test if FODMAPs are the culprit, scientists at Monash University in Melbourne ran clinical trials where they altered dietary FODMAPs and tracked IBS symptoms. Complementary studies were conducted in Canada, Denmark, Sweden, the UK and the US. On average, 7 in 10 people on a low-FODMAP diet noticed an improvement in IBS symptoms.

But not everyone is convinced. A 2017 scientific review of nine FODMAP trials noted they all had a “high risk of bias” in aspects of their design and theorised any benefits from the diet may be due to the placebo effect. However, another study last year found the low-FODMAP diet offered “adequate” symptom relief compared with a sham “placebo” eating regime.

Monash University researchers have also studied the diet’s effectiveness in conditions with IBS-like symptoms, such as endometriosis. However, this research is still in the early stages.

The role of FODMAPs

If the eating plan can reduce gas and bloat, why shouldn’t everyone give it a try? One reason is the important role FODMAPs play in digestive health.

Some FODMAP carbs, including fructans and galacto-oligosaccharides, are known as “prebiotics”. These are an important food source for the “probiotic” or “good” bacteria living in our gut.

Monash University nutrition researcher Dr Jane Muir says the restrictive nature of the low-FODMAP diet can make it hard to meet your body’s nutritional needs. Without the help of a dietician, dietary intake of calcium and dietary fibre can be reduced on this diet, she says.

Even IBS sufferers are only advised to go on the eating plan temporarily, Dr Muir says. Once symptoms have stabilised (which can take 2 to 6 weeks), foods with different types of FODMAPs are slowly reintroduced with the help of a specialist to see if they trigger IBS symptoms.

“The goal is to achieve good symptom control without overly restricting foods,” she says.

Seek doctor's advice first

There’s no need for anyone without an IBS diagnosis to pay attention to the FODMAPs they consume or choose a low-FODMAP product over a standard variety, Dr Muir says.

The low-FODMAP diet should only be undertaken under the supervision of a specialist or trained dietician. “We don’t want the low-FODMAP diet becoming the next gluten-free diet craze,” she says.

Monash University runs a low-FODMAP food certification scheme. Certified products must carry a warning in all advertising that “a strict low-FODMAP diet should only be commenced under the supervision of a healthcare professional”.

Monash University researcher Dr Marina Iacovou says a doctor’s input is critical because IBS symptoms can also indicate other diseases, from inflammatory bowel disease and coeliac disease to colorectal cancer. “It’s not something people should self-diagnose,” she says.

None of the specialty products we saw on supermarket shelves had similar advice to Monash’s.

In our view, one company producing FODMAP-specialty products pushed the envelope with its advice. Several Orgran products, including Buckwheat Crispibread, bear a “tummy friendly” logo on the pack, which tells consumers a product is “not just gluten-free, but made without fructose, onion, garlic and pea flour”.

Orgran’s website gave little information about FODMAPs but linked to another that tells readers: “it’s not just IBS sufferers who can benefit from a low FODMAP diet. Anyone can switch to it, or at least follow some of the techniques to help create a healthier lifestyle.”

We asked Orgran why it pointed its customers to the website. The company removed the link and said it “is currently reviewing the content on this page”.

Low-FODMAP logos

If you’re looking for a low-FODMAP food, you’ll likely spot two logos on products.

One is the Monash University “Low FODMAP Certified” logo. The other is “FODMAP-Friendly”, a certification co-founded by Australian dietician Sue Shepherd.

The logos don’t mean a product is free from FODMAPs, but that it doesn’t exceed certain thresholds. Monash University bases these cut-offs on its published research.

FODMAP-Friendly didn’t give us much detail about its thresholds, except to say they’ve been determined by “scientific research”.

Companies pay an annual fee to use the logos on their products. Both schemes independently re-test FODMAP content regularly and products can be subject to spot checks.

Some pre-prepared foods, particularly vegetable soups and Asian-style sauces, almost always contain onions and garlic in their ingredients list – the logo can be a timesaver here.

Cheaper options

Some products are naturally low in FODMAPs, so those on the diet don’t always have to look for a logo to find something appropriate to eat. As specialty products are often more expensive, you can save money by reading labels to find options – or cook from scratch following dietary guidelines.

  • Fodmapped For You Red Wine + Italian Herbs Pasta Sauce $6.29 for 375g


  • Delmaine Passata with Basil $4.39 for 670g

  • Fodmapped For You Roasted Pumpkin Soup $9.29 for 500g


  • Watties Condensed Tomato Soup $1.50 for 420g

  • Fodmapped For You Green Curry Simmer Sauce $6.29 for 200g


  • Passage To Asia Pad See Ew Stir-Fry SauceA $3.59 for 200g

  • Orgran Crispibread $5.45 for 125g


  • Arnotts Cruskits Rice $3.00 for 125g

GUIDE Alternative versions were assessed for FODMAP content based on the Monash University low-FODMAP diet guide app's categorisation of the ingredient list. A food cannot be definitively categorised as low-FODMAP without being tested. If a product is assumed to be low in FODMAPs, patients are advised to try the food in small quantities to assess their tolerance. Nutritional value was not assessed. Aprepared without onion and with one cup broccoli heads and gluten-free noodles.

Taste test

To find out if you lose flavour when you sacrifice FODMAPs, we held a taste test comparing 2 low-FODMAP certified products against standard alternatives.

Without knowing which was which, 10 Consumer staffers (none with IBS) tried Fodmapped For You Slow Roasted Vegetables Pasta Sauce and Watties Garden Vegetable Pasta Sauce.

Fodmapped For You Butter Chicken Curry Simmer Sauce was also pitted against Watties Curry Creation Butter Chicken Sauce.

When we asked for their preferences, the Watties products gained 6 votes to Fodmapped For You’s 4.

Some of our panellists found the low-FODMAP pasta sauce “a bit bland”, but others preferred the simplicity.

However, of the 4 who preferred the Fodmapped For You butter chicken, just 2 would have it again. Six panellists found its spices overpowering, with one describing it as “cinnamon heavy”.

By Olivia Wannan
Investigative Writer

Member comments

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stella s.
21 Aug 2018
Stella 2018

I was given the low FODMAP diet by my GP after suffering IBS for years. I went on line to find out more information and came across a dietician with so much information on this, plus recipes. I am following his teachings --- two and half weeks into this I feel better already. What I find difficult to understand is why people would buy ready made products for this, they are really a rip off, someone saw a way to make money out of peoples suffering. They must contain preservatives, and this is one of the things that upset me. There are so many easy recipes online.

Sue D.
21 Jul 2018
Helpful guide

My GP referred me to the FODMAP resources to help work out which foods were causing problems. I've found it to be a very useful guide and over the past two years have eliminated some foods including onions, garlic, kidney beans, chick peas and most dairy foods from my diet and limited others such as apples and stone fruit.
I don't think there's any need to buy special FODMAP foods, although I wish restaurants would recognise that there are a lot of people who can't tolerate onions and garlic.

Margaret B.
17 Jul 2018
On this diet

A dietitian put me on this diet early last year after a year of very unpleasant symptoms. I had tried a similar diet about 10 years ago after a dietitian suggested that some of the fruit I was eating might be a problem. The fructose test was not conclusive, but I continued to limit quantities of certain fruit. Last year onions proved to be the main issue and I no longer have them.

I have been on the low-salicyate diet (researched by the Royal Prince Alfred Hospital in Sydney) for 20 years after being put on that by another dietitian. Before that I was told to reduce lactose intake in 1990 and wheat intake in 1994. Balancing these diets is quite difficult but it keeps me well if I do so. I certainly react if I accidentally eat too much of certain foods.

These diets are not well-known and many eating places can not cater for them. Onions are added to almost every dish now. My safe meal is a roast provided the protein is cut from the animal and does not come sliced in gravy.