5 things you need to know about the Low FODMAP Diet

For an introduction to the Low FODMAP diet, please read our earlier blog post ‘The Low FODMAP diet: What is it and can it help my IBS?’.

  1. The diet is only for 8 weeks and must not be done for much longer as it can negatively affect the bacteria in your gut. There are 3 important phases to the diet:
  • Elimination of high FODMAP foods for 4-8 weeks using the correct information: Either from a registered dietitian who has been trained in the FODMAP diet or from the Monash University website. Do not use other lists on the internet as they are often incomplete, incorrect or not up to date. (For a list of UK trained FODMAP dietitians see the Kings College London website.)
  • Reintroduction phase after the 4-8 week period, using a step wise process to determine your personal threshold of tolerance to the individual foods. Each food is reintroduced individually over 3 consecutive days in increasing amounts. You must remain on the strict FODMAP diet throughout this period so that only one FODMAP food is in the diet at any one time. This way, if you suffer symptoms you know that it can only be that one food that is causing the problem.
  • Long term self management where you maintain control of your symptoms having found the FODMAP foods which were responsible and having returned a predominantly normal varied diet.
  1. Onion and garlic are not allowed on the diet. However, don’t be tempted to cook with onion and garlic e.g. in stew, casserole, bolognaise etc, and then remove them before eating the food, as the fructans will have leached into the sauce and will still take effect. Hence, use chives, green part of spring onions or asafoetida powder instead (Indian herb onion replacer) and you can use garlic oil (as the fructans do not pass into the oil).
  2. Historically spelt flour was allowed on the FODMAP diet. However, it has been reanalysed and now the only spelt you are allowed is 100% spelt flour sourdough In this form the fructans in the spelt flour have been fermented by the sourdough method making the bread low in FODMAPs. All other spelt breads or products are not allowed.
  3. Soya milk has recently been reanalysed and it now appears that soya milk made from soya beans is high in FODMAPs. It is suggested that you stick to a maximum of 60ml per day. However, soya milk made from soya protein is low FODMAP but is very difficult to find in the UK.
  4. Lactose: For those people who need to reduce lactose in their diet as part of the FODMAP regimen (people with constipation rarely need to remove lactose), then remember that it’s about having a low lactose diet and NOT a lactose free or dairy free diet. Lactose is only particularly high in milk, yogurt and ice-cream. For these you can use alternative such as Lactofree products or alternative plant based dairy products. Normal fat content cheese, e.g. cheddar, brie, blue cheese, mozzarella, feta, edam, goats cheese etc. are all fine on the FODMAP diet, as is butter, cream, sour cream, crème fraiche and dark chocolate. You can still have up to 30g of milk chocolate per day!

Have you tried the Low FODMAP Diet? How did you get on? We’d love to hear from you! Email hello@mysymptoms.net

Marianne Williams

About Marianne Williams

Marianne is a Registered Dietitian in the UK and was awarded ‘Dietitian of the Year’ in 2012. Marianne set up the first NHS primary care dietetic-led gastroenterology clinic in the UK in 2011 specialising in dietary treatment for adults with IBS and gastrointestinal allergy.

One Comment

  • Sarah Stone says:

    This bit about low lactose rather than low dairy is quite a revelation for me thank you so much! I was really hesitant about including dairy in things as one of my sons had such a reaction to dairy rather than lactose that I’d assumed it was a low fodmap thing as he’s a twin and his brother is very sensitive to lots of high fodmap foods, so I’d chucked the baby out with the bath water so to speak. So we’re now feeling brave enough to try a small amount of butter and progress to cheeses and creams all being well.

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