IBS diet: low FODMAP explained by a dietitian

You may have come across the term low FODMAP diet while researching digestive health or looking for ways to manage digestive discomfort. But what exactly is a FODMAP diet and how does it work? To help explain, we’ve spoken to our nutritionist, Molly Arnold.

A low FODMAP diet is a short-term dietary approach that involves reducing certain types of carbohydrates known as Fermentable, Oligo-saccharides, Di-saccharides, Mono-saccharides and Polyols.¹ These carbohydrates are naturally found in many everyday foods. “It's worth checking food labels carefully, as ingredients such as onion, garlic and certain sweeteners can appear in sauces, soups and ready meals, even when they're not obvious from the name of the product,” says Molly.² For most people, FODMAPs are a normal part of a healthy diet. However, some people are sensitive to them and may experience digestive symptoms when consuming foods high in FODMAPs.

“One common misconception is that a low FODMAP diet is highly restrictive. While some foods are temporarily limited, there are still plenty of nutritious and enjoyable low FODMAP foods available,” says Molly. “Building meals around these foods can help keep your diet balanced while you're working through the elimination phase.”^4,5

“Many foods high in FODMAPs are nutritious choices for the general population. They're only temporarily reduced during the elimination phase to help identify individual tolerances before being reintroduced wherever possible,” says Molly.⁶ “A food isn't always simply 'high' or 'low' in FODMAPs. In many cases, the amount you eat makes the difference, with some foods remaining low FODMAP in smaller portions but becoming high FODMAP when larger servings are consumed.”^4,6

FODMAPs aren't absorbed particularly well in the small intestine. This means, they travel further through the digestive system to the large intestine where they attract water and are fermented by gut bacteria.¹ The fermentation process produces gas, while the extra water drawn into the gut can affect bowel movements.⁸ In sensitive people, this may contribute to symptoms such as:⁹

The low FODMAP diet is one of the most researched diets – and while it isn't suitable as a lifelong restrictive plan, it can help identify trigger foods and provide valuable insight into how your body responds to different foods. With support from a FODMAP-trained dietitian, many people can create a personalised eating plan that includes a wide range of nutritious foods while minimising digestive discomfort.

Disclaimer – This article provides informational advice and is not a substitute for medical care. Working with experts for accuracy, we take great care to ensure the information is up-to-date and relevant. However, you should always consult your GP or healthcare professional before using supplements or alternative products, particularly if you have medical conditions or are under supervision.