Cutting out sugar and starch is as effective for IBS as current recommendations

Symptoms for patients with the gastrointestinal disease IBS improved as much by eating less sugar and starch as for those who followed FODMAP – the diet currently recommended to patients. The results, presented in a new study from Lund University in Sweden, also show that weight loss is greater and sugar cravings are reduced among those who follow the starch and sucrose-reduced diet.

Bodil Ohlsson is a professor at Lund University and consultant at Skåne University Hospital. Her choice to investigate the role of sugars and starches in IBS is linked to a geneticist’s discovery: a genetic variation that hinders the breakdown of sugars and starches in the gut is overrepresented among IBS patients.

“‘Let’s try giving these patients less sugar and starch,’ we thought,” says Bodil Ohlsson.

A few years ago, she led a study involving 105 people with IBS. For four weeks, they ate significantly less sugar and starch, known as the starch and sucrose-reduced diet (SSRD). In addition to sweet treats, highly processed food – “ready meals” – were also to be avoided. The results of that study showed that the SSRD diet greatly reduced IBS symptoms. The most common symptoms of IBS are recurring pain and tightness in the abdomen, and diarrhoea and/or constipation. 

The current study, now published in the scientific journal Nutrients, addresses a question that no other research has previously: how does SSRD compare to the current dietary recommendation for IBS, the FODMAP diet? FODMAP is a stricter, more regulated diet where lists of foods that are allowed/not allowed must be consistently followed. This diet also excludes gluten and lactose.

“We launched this study in 2022 to compare SSRD and Low FODMAP. One hundred and fifty-five patients diagnosed with IBS were included and randomly allocated to follow either SSRD or Low FODMAP for four weeks. They were not allowed to have been on a diet at the start of the trial, but rather ate ‘everything’,” says Bodil Ohlsson.

Participants in both groups had to follow the basic principles of each diet. But they chose how often or regularly they ate. In both groups, regardless of diet, IBS symptoms improved in 75-80 per cent of the patients, which according to Bodil Ohlsson “was even better than we expected”. In addition, weight loss after four weeks was greater in the SSRD group. Sugar cravings also decreased the most in this group, which is positive, as IBS patients weigh more on average than healthy people, says Bodil Ohlsson.

“We wouldn’t really even call SSRD a diet. It’s how everyone should eat, not just those with IBS. And unlike Low FODMAP, SSRD is easy to understand and easier to follow. You can eat everything when you are invited to dinner, just less of certain things. If you rest your stomach for the rest of the week, you can indulge a little one day!” says Bodil Ohlsson.