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10 things you need to know about the low FODMAP diet

10 things you need to know about the low FODMAP diet

by FoodMaestro | 9 August 2016

By: Hannah Hunter, a HCPC registered dietitian trained in FODMAPs at King's College London.

While you’re considering or even if you’re already on a low FODMAP diet there are some key points you need to know.

1 – Consult your doctor first

Before you embark on a Low FODMAP diet you should take the same precautions as you would before making any significant dietary or lifestyle change and talk to your doctor. This diet may not be right for you and it is important that you get some individual advice. Your doctor will also ensure that the relevant tests have been performed, for instance having a blood test to screen for coeliac disease is crucial. 

2 - It is not a gluten free diet

People with coeliac disease need to follow a strict gluten free diet, avoiding even tiny traces of gluten and being careful about contamination. This is not the case for the low FODMAP diet, when lager amounts are usually required to trigger symptoms and foods containing gluten such as soy sauce and sourdough spelt bread are allowed. Additionally, many gluten free products contain high FODMAP ingredients such as fruit or inulin and are not suitable.

3 – It is Not a dairy free diet

Although lactose is restricted on the low FODMAP diet, dairy does not need to be avoided completely unless you have cow’s milk allergy. Dairy products are a useful source of many nutrients, particularly calcium (see our blog on calcium). Many dairy foods are low in lactose, such as hard cheese, cream and lactose free milk/ yoghurt. Most people will tolerate small amounts of lactose, such as normal milk in tea or a few spoonfuls of yogurt with a meal (see our blog on lactose guidelines).

4 – Reintroduction is important

It is recommended that you follow the restriction phase (Stage 1) for 4-8 weeks only. You are unlikely to get any further improvements beyond this point. Continuing to be restrictive risks nutritional deficiencies, limits socialising and can impact your food budget. More importantly, a low FODMAP diet has been shown to affect the balance of your gut bacteria. FODMAPs have a prebiotic effect: they help good bacteria to grow so restricting them may have negative effects. Reintroducing FODMAPs and finding your tolerance levels is therefore important. FoodMaestro can help guide you through this phase (Stage 2). 

Low FODMAP diet

5 – There can be side effects

Although it does not happen to everyone, many people who trial the low FODMAP diet find themselves more constipated, even if they are usually prone to diarrhoea. If this happens to you, ensure you are getting enough fibre and fluids. Good sources of low FODMAP fibre include fruits and vegetables, oats and seeds. If it does not improve or worsens, talk to your doctor or dietitian for advice. 

6 – Slip-ups are allowed

Maintaining a strict low FODMAP diet is a challenge, particularly in the beginning when you are learning what you can and can’t eat. It is particularly difficult when dining outside of the home and therefore sometimes it is necessary to deviate from the diet. As long as this is not a frequent occurrence during the restriction phase, this should not have an impact on your treatment plan.

7 - Eating out is possible

Avoiding FODMAPs at home is one challenge but an even bigger challenge when eating in restaurants and friends’ houses. However, with a bit of planning and communication with catering staff (or friends) it is definitely possible. It can even be enjoyable, especially if you avoid symptoms and you may also find others are interested in your diet as they may have symptoms themselves (see our blog for tips out eating out).

8 – FODMAP advice is still evolving

As with all arms of medicine and science, new research can change the landscape. The work on FODMAPs is still relatively young so it’s not uncommon to see updates in the FODMAP content of foods and advice given to people. You can keep up to date here as we do everything we can to keep in line with all of the latest developments and the FODMAP by FM app is regularly updated as new information comes out.

9 – Seeing a dietitian is important

As this is a complicated diet, it is important that you have access to the right support. A trained dietitian is helpful for many reasons: ensuring the diet is appropriate for you, explaining the ins and outs of FODMAPs in detail, providing you an accurate list of foods, personalizing advice to your circumstances, and explaining the complex reintroduction process. For a referral to a dietitian, talk to your GP or hospital consultant. Read more about the benefits of seeing a dietitian in Hannah’s blog.

10 - It doesn’t work for everyone

This is possibly one of the most important things to bear in mind. Current research shows that the percentage of people who respond to a low FODMAP diet is high (3 in 4). That still leaves 1 in 4 who won’t respond. If you’re in that group or if you’re following the diet perfectly and not seeing results, then it’s possible that low FODMAPs isn’t for you. Talk to your doctor or dietitian about other options for managing your symptoms.

Related links:

Articles by Dietitian Hanna Hunter: