Written by Lisa Kunstler, FodShop Nutritionist, Personal Trainer, and Group Fitness Instructor
An Introduction to Irritable Bowel Syndrome
Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder with symptoms of abdominal pain, flatulence, bloating, diarrhoea, and constipation that significantly affect quality of life. There are no known causes of IBS however, changes in the microbiome, heightened gut sensitivity, and chemical imbalances may be responsible.
There is no cure for IBS however, symptoms can be managed by following a low FODMAP diet. FODMAP stands for fermented oligosaccharides, disaccharides, monosaccharides, and polyols. Foods including FODMAPs are often a trigger for IBS symptoms and by limiting these, we can minimise episodes. However, with many foods high in FODMAPs including fruits, vegetables, grains, and dairy, there are concerns that limiting these foods may result in weight loss, and in some cases, gain.
IBS and Weight Gain
If a low FODMAP diet is poorly followed, there can be concerns for weight gain. Some people will altogether eliminate whole food groups that are essential to our health, such as whole grains, vegetables, and fruits, just to prevent their symptoms. Opting for foods that are energy dense and nutrient poor as a replacement may cause weight gain and other concerns like low fibre and high refined sugar intake.
There are plenty of whole grains, vegetables, and fruits that can be enjoyed on a low FODMAP diet at an appropriate serving size. Below are some examples of low FODMAP alternatives that are safe by serving size according to the Monash University Low FODMAP App.
- 1 cup eggplant
- ¾ cup bean sprouts
- 15 green beans
- ½ cup green capsicum
- 1 medium carrot
- ½ cup Lebanese cucumber
- 1 cup iceberg lettuce
- 1 cup oyster mushrooms
- 15 small olives
- 1 medium parsnip
- ½ cup white potato
- 2 cups English spinach
- 1 medium firm common banana
- 1 medium clementine
- 5 dates
- 2 small green kiwis
- 1 medium mandarin
- 1 medium navel orange
- 1 cup yellow papaya
- 1 cup pineapple
- 2 slices gluten free bread
- ½ cup cooked couscous
- 2/3 cup buckwheat flour
- 2/3 cup gluten free flour
- ½ cup rolled oats
- 1 cup gluten free pasta
- 1 cup cooked polenta
- 1 cup cooked quinoa
- 1 cup cooked brown or white rice
Individuals with IBS can also struggle with anxiety around physical activity and socials situations with the suddenness of symptoms. The stress of having to urgently use the bathroom may deter individuals from leaving the house, creating less opportunity for physical activity. Low intensity exercises, like yoga, walking, and Pilates, are known to be great ways to improve gut mobility and maintain a healthy weight without triggering symptoms.
IBS and Weight Loss
IBS can also go the other way, with many individuals struggling with weight loss following a low FODMAP diet. Anxiety around eating is common and to prevent symptoms from occurring, individuals sometimes skip meals, limit food, or follow a too restrictive diet.
The list above includes great options for low FODMAP alternatives however, it is also important to keep protein intake high to prevent weight loss. Thankfully, foods high in protein are often low FODMAP, like fish and seafood, lean, unprocessed meats, and firm tofu.
Try to eat smaller, frequent meals rather than larger meals that will lessen the chance of symptoms but provide an adequate caloric intake. Low FODMAP dressings like mayonnaise, cheese like cheddar, olive oil, nuts, and starchy vegetables are good options for a higher caloric intake.
If you are new to the low FODMAP diet, it is essential to seek help. Visit your General Practitioner or Accredited Practising Dietitian to get help on how to follow a low FODMAP diet without putting yourself at risk of unhealthy weight gain or loss.
Remember that there are more foods than just those within the list above that are low FODMAP by serving size and will provide you with plenty of healthy nutrients to maintain your weight and health. For more information on low FODMAP foods by serving size, check out the Monash University Low FODMAP App.
Hamaguchi T, Tayama J, Suzuki M, Nakaya N, Takizawa H, et al. (2020) The effects of locomotor activity on gastrointestinal symptoms of irritable bowel syndrome among younger people: An observational study. PLOS ONE 15(5): e0234089. https://doi.org/10.1371/journal.pone.0234089
Harer KN. Irritable Bowel Syndrome, Disordered Eating, and Eating Disorders. Gastroenterol Hepatol (N Y). 2019 May;15(5):280-282. PMID: 31360143; PMCID: PMC6589841.
Kopczyńska M, Mokros Ł, Pietras T, Małecka-Panas E. Quality of life and depression in patients with irritable bowel syndrome. Prz Gastroenterol. 2018;13(2):102-108. doi: 10.5114/pg.2018.75819. Epub 2018 May 16. PMID: 30002768; PMCID: PMC6040097.
Monash University Low FODMAP App https://www.monashfodmap.com/ibs-central/i-have-ibs/get-the-app/