Are you fed up of trying to lose weight, but feeling frustrated that healthy food trigger your IBS symptoms? 

It can feel like typical weight loss advice tells you to eat food that makes you feel bloated, gives you stomach pains or send you running to the bathroom. 

I work with clients who have IBS, and most typically also want to lose some weight, and I help resolve digestive issues alongside a diet plan.

If you’re struggling with this you’re not alone. The majority of adults in the UK are overweight or obese, and IBS affects nearly 2 in 10 people, so many many people experience a sensitive digestion, and are trying to lose weight. 

Some studies have found links between IBS and weight, one study found 30% of people with a BMI of over 30 had IBS, compared to an average 10-15% incidence in the general population. 

How to lose weight with IBS

As with everything in nutrition, there is no ‘one size fits all’ approach.

Your IBS symptoms will be very different from your neighbours. And what helps one person lose weight might not work for another person. 

As well as looking at weight loss diets for IBS it’s also really important to consider factors like your:

• exercise – intensity, frequency and duration
• sleep – how long, quality
• mood – stress levels
• hormones – women’s menstrual cycle
• timing of food – when, and how you are eating

Generally, as an IBS nutritionist working with my 1:1 weight loss clients I like to focus on including foods that will help to fill us up and keep us well nourished instead of removing foods. 

When we restrict our intake of energy (or feel like we are restricting ourselves) it can be mentally challenging, sometimes leading to binging or giving up the weight loss altogether.

Cutting out processed foods

However, removing obviously high calorie, overly processed foods from your diet will help to reduce your energy intake. 

This includes things like

• crisps,
• chocolate,
• cream,
• ready meals
• pre-packaged cakes and biscuits. 

These tend to be high caloric density foods with little nutritional value.

Foods high in salt and sugar can cause water retention, and bloating, which may make IBS symptoms worse. 

Which carbs to eat for weight loss with IBS

Carbohydrates are our main source of energy, but how we consume them can influence digestion and weight gain.

Ideally, you would avoid too many simple carbohydrates like white bread or white pasta and switch to whole grain versions.

This is because whole grains include more nutrients, fibre and protein. Wholegrains are associated with healthy heart, better bowel movements and gut health, as well as weight loss.

You’ll find wholegrain bread and pasta more filling, which may help you eat less calories overall. If you react to high fibre foods this might make you anxious, and so make any diet changes very carefully. 

How to do it:

Often when people with IBS react to certain foods it can be dose-dependent so you may want to transition from white pasta to brown pasta by cooking half and half for a period of time. Slowly increase the whole grain versions. 

Many people with IBS find sourdough easier to digest, because some of the fibre has been digested in the fermentation process before baking. Sourdough bread has lower levels of polysaccharides called fructans, which is highly fermentable by out gut bacteria. 

You may find pasta or bread made from spelt, rye or buckwheat is easier to digest as some people with IBS react to fructans in wheat.

Other wholegrains to include are oats, quinoa, spelt. 

How to eat fibre with IBS

Fibre is really important for helping us to feel full, as well as feeding the beneficial gut microbes. 

High fibre foods are whole grains, nuts, seeds, vegetables, fruits and pulses like lentils. 

Many people with IBS struggle to increase their fibre intake. 

How to do it:

If you’re very sensitive to high fibre foods start very slowly, and always drink enough fluids. Fibre without water will lead to constipation.

Focusing on the low FODMAP foods first maybe something that help you build up to a higher fibre diet. For example:

• Kiwis are good for anyone with IBS and constipation because they can encourage a healthy bowel movement.
• Try adding some greens to your dinner, even blending up some spinach into sauces may help to begin with.
• Berries like raspberries or blueberries can make a good snack, or addition to a breakfast.

Increase protein to avoid hunger

Protein from meat, fish, eggs, nuts and seeds, pulses and tofu can help to keep us fuller for longer. 

Aim to include sufficient protein at every meal and snack to help keep your blood sugars balanced. 

If you increase protein when you have IBS you may find meat sits in your stomach for a long time and leads you feeling heavy. This may be down to insufficient stomach acid to help break down the proteins.

How to do it:

Some people find eating bitter foods such as rocket, endive, chicory, or lemon juice can help to stimulate the digestive processes, and aid protein breakdown. 

You can also focus on chewing your food really well to help kick start the digestion in your mouth and reduce the pressure put on your digestive system by unchewed lumps of food. 

Healthy Fats for IBS

It is important to include healthy fats in our diet whether we want to lose weight or not. And if you eat a lot of saturated fats, then reducing these will also help cut calories from your diet.

We need fats to help us absorb certain vitamins A, D, E and K, and we need fats for cell health, skin health and our hormones. Cutting out all fat from your diet is not a good idea, but fat does contain more energy than protein or carbs per gram.

How to do it:

Reduce high fat foods such as deep fried chicken, chips or baked goods like cakes.

Fats to include: Snack on a handful of nuts such as walnuts, macadamia or seeds. Nuts like cashews or pistachios are higher in FODMAPs are more likely to cause IBS symptoms. Include Omega 3 rich fish twice a week such as mackerel salmon or sardines. Eat avocado if well tolerated. 

Hydrate – aim for 8 glasses of water 

Ensure you’re drinking enough water. When we are very thirsty sometimes our body mistakes these signals as hunger and we end up snacking more than we need to. If you’re aiming to lose weight ensure you are drinking enough fluids throughout a day. 

How to do it:

Drink around two litres of water spaced through the day.

Avoid alcohol – Drinking alcohol can lead to weight gain because often you are drinking a lot of energy.  In addition you may find yourself snacking on crisps and other foods whilst drinking or the next day if you feel a little bit hungover. 

Moderate exercise for weight loss with IBS

One of the best ways to lose weight is to do some high intensity exercise.  However, for people with IBS the intensity can trigger symptoms and leave you rushing to the bathroom. 

Some studies have shown that when we do high intensity exercise blood rushes from the internal organs to our muscles which can in some people create problems for people with IBS. Read more about the best and worst exercise for IBS. 

How to do it:

Try yoga, walking, swimming or other moderate exercise to get moving, without setting off your stomach. 

Slow down to eat

When we eat very quickly, not chewing food properly this can lead to to strain on your digestive system by swallowing large chunks of foods that have not been chewed up.

In addition when we eat very quickly we are more likely to miss the satiety signals sent by our digestive hormones back to the brain which tell us we have eaten enough food. 

This means we might eat more than we were intending to because with eaten so quickly.  

This is good advice for anyone not just those who want to lose weight. 

Simple changes like chewing your food properly before each mouthful can really make a difference to the quality of your digestion. Read – How many times should I chew my food?

How to do it: 

Sit down to eat, and chew each mouthful properly. 

Use a food diary for weight loss

I’ve previously written about how tracking our food can improve the quality. You may find that the practice of writing down what you eat shows up all those things you previously forgot about.

Based on working with lots of clients, I suggest you only do this for a few days, because it’s easy to get a little bit obsessive about recording everything.

We also get a good insight into symptom triggers when we have a record of what we’ve eaten and done over the last few weeks. Use a  journal or simple note book to record what you have been eating and also think about what else could have impacted your symptoms, such as:

• menstrual cycle
• stress levels
• exercise
• sleep.

Work with a professional

Losing weight with IBS isn’t impossible, but it can be more difficult due to how you react to ‘healthy foods’.

If you want to change your diet but feel like you react to everything you eat please contact me too to talk about what you need help with. 

I can help you find a diet that works for you and your particular health conditions, your unique situation so that you can achieve your health goals.