Ep.50 – How to gain weight with IBS
19 Jun, 2024

Episode Intro

Why is it so hard to put on weight if you've got IBS? Especially when you feel like you're really eating enough already. Unexpected or undesired weight loss can be more prevalent with people who've got a diarrhoea predominant type of IBS because often the transit time of food doesn't really allow for proper digestion. But there are also people with constipation in a low body weight who really struggle to put on any weight. In this episode of the Inside Knowledge podcast, I'll be sharing my advice on how to increase your energy intake without worsening your digestive symptoms in either SIBO or IBS. And you'll also learn how to increase your appetite so you actually want to eat more.

Podcast transcript

Welcome to episode 50 of the Inside Knowledge podcast. I’m Anna Mapson. This episode I’ve been meaning to record for a little while. I did two episodes a few weeks ago about how to lose weight. And that was also a popular request. But how to gain weight is something that I know so many people struggle with when they’ve got severe digestive conditions.

Gaining weight with IBS can be tough

If this is something you struggle with, maybe you just feel like it’s impossible to gain weight. Because every time you try to eat more. Or you try to eat different foods you get a flare up.

Maybe you’ve been on a strict elimination diet for a really long time. Or you’ve just been skipping meals because you’re trying to give your digestion a break. And feel like if you don’t eat, then you’re going to feel better or at least not feel any worse.

But over time that can lead to a real reduced energy intake.

What is underweight?

So what does it even mean to be underweight? What am I actually talking about? Well, Often we use the body mass index, your BMI. That’s adjusted for your height and your gender, but it doesn’t take into account any muscle mass.

It’s also important to look at your body composition.

For example, somebody who is in a very lean body could also be not really nourishing themselves because their body fat percentage is too low. You may have a normal BMI, but you may, if you’re completely ripped like a bodybuilder, you may have such a low body fat that it can impact on your health.

And that is really why we’re talking about how a low body weight that’s too small for your height.

BMI can indicate weight safety

You know, the BMI is not perfect, but it can give you an indication of your body size. How it compares to other people who are the same height as you, for example.

Using BMI, which, as I said, is a kind of crude, way of just adjusting for height and body size and weight. We’re looking at a BMI of less than 18.5. That is considered underweight.

But as I said, people who are in a very muscly body, like sometimes bodybuilders will have a very low body fat percentage and yet have a normal BMI. And that is because it doesn’t take into account muscle mass.

Being underweight can lead to health issues

The problems with being in a very small body and not nourishing yourself with sufficient, broad and balanced diet is it means you can get problems with your immune health.

Immune health

So maybe you’re getting more infections and that can be down to a lack of antioxidant intake, vitamins, minerals that keep our immune system really healthy.

Menstrual health

If you’re not getting enough energy, a really key sign for women is that you lose your periods. That is red flag for being underweight and not having enough energy intake.

Bone health

You can have problems with bone density, so leading to osteoporosis, even at quite a young age. And this is down to, again, not having enough muscle mass that is stressing the bones and not working your body effectively. But also not having enough of the key nutrients that help build bones.

Muscle wastage

And also, muscle wastage. So when you’re in a very small body with a very underweight body size, you will get muscle wastage. Your body’s drawing nutrients out from your muscles, particularly protein.

People with IBS can lose weight

People with IBS tend to lose weight due to all these kind of restrictive diets. Maybe you’re cutting out certain food groups to get rid of your trigger foods. But the problem is this list of what you can’t eat can get very very long and it just leaves you without a balanced diet

I’ve worked with lots of people who feel pretty stuck in this place that they want to gain weight But they can’t work out how to increase the foods without going back to really terrible digestive symptoms.

Undereating can cause digestive symptoms

One of the main reasons I wanted to do this podcast as well is to explain that under eating can actually cause digestive symptoms. So we know that undereating and malnutrition can affect the function of your digestive tract. It can give you slow motility, causing problems with constipation just because you’re not getting enough food and slowing down the gut.

You can also get malnutrition which leads to electrolyte disturbances and this can in turn cause motility issues. You can get problems with gastric emptying, so that’s when your stomach is emptying into your small intestine. There are also problems with feeling very full. So post prandial fullness, it’s called. Which is basically how you feel after you’ve eaten, bloating, feeling very full very quickly, and excessive nausea.

These are really, really common in people who under eat, and these are really common in people who have IBS.

Undereating can cause IBS symptoms

One of the things I really work with people on a lot is how sometimes you’re under eating is contributing to your symptoms. I know that you feel like you’re managing it through not eating but sometimes what you need to do is to try eating more. And obviously we need to work on how to do that and I’m going to give you a few tips later on in this episode.

Unexplained weight loss is a red flag

Before I get into a few tips on how to gain weight, I want you to think about, is your weight loss unexplained? So, if you recently lost weight without meaning to. Especially if it’s been quite quickly, it is really important for you to get checked over by a doctor.

Think about how much weight you might have lost and in what time period.

If you’re not somebody who’s weighing your body recently, that’s absolutely fine. Just think about Have you dropped a couple of clothes sizes over a couple of months? A shorter period of time to lose a significant amount of weight?

Weight loss red flags

Which may indicate there’s something else going on. So the NHS suggests a loss of more than about 10kg in 3 months would be definitely a red flag for investigation.

Or if you’re looking at like 5 -10 percent of your body weight. So think about how much you’re losing. That has happened and has it happened quickly?

Can your weight loss be explained by not eating enough?

And actually, is it down to you realistically not eating enough food? Maybe you’ve been fasting, skipping meals. Like I said, reducing down portion sizing. Or is it down to something that you don’t know?

You feel like you’ve eaten the same amount of food, but you’ve rapidly lost weight. Things that doctors might want to check out would be inflammatory bowel disease, coeliac disease, an overactive thyroid, or some cancers as well. So, it really is better important to speak to a GP or gastroenterologist to rule these out.

People with IBS can lose weight

People with digestive issues like SIBO or IBS, the weight loss is explained by you not eating as much as you were. And sometimes it’s easy to see how what you’re eating Could be causing weight loss, but you might not know how to break out of it.

Am elimination diet

So common restrictions are going on a very low fat diet, and that could be because you’re not breaking down fats very well.

You get diarrhoea and stomach cramps. It could be related to bile acid malabsorption. Maybe you’ve cut out a lot of other high fat foods like dairy and you no longer eat any cheese or creams. Maybe you find protein really difficult to digest and you have cut right back on meats.

And then obviously the FODMAP diet, so you might have really reduced the amounts of vegetables and fruits that you eat and also you’ve cut out maybe dairy. Gluten, soya, like sugary foods. Just trying to find the thing that is your trigger. So I’m not at all trying to say that the blame is on you. I really understand that it is a tough place to be.

To gain weight with IBS you’ll need more calories

Ultimately, if you want to gain weight, you need to eat more calories than you burn off every day. And it’s important to do this slowly and ideally using healthy foods that are going to support your body. Give you what you need. But essentially it boils down to eating more calories.

So an ideal way to increase it would be around 500 calories a day over time, like maybe do an extra 500 calories a day for a week, and then another extra 500 calories, and then you’re slowly increasing it that way. Or possibly you also need to eat more often to eat bigger portions of the foods that you’re already eating.

You need to eat more volume and you also need to eat more energy dense foods.  I’ll have some tips on that for you in just a moment.

Are you afraid to eat with IBS?

The other thing I wanted to mention is whether your fear of the consequences of eating could potentially be holding you back from taking these steps to increase your diet.

If you haven’t already, listen to episode 43 where I talk about ARFID, that is Avoidant Restrictive Food Intake Disorder. This is a disorder where people really struggle to increase their food variety and volume because They have a lot of fear about the consequences of what they’re going to eat.

ARFID – fear of digestive consequences

This is really understandable in people who’ve got really bad digestive distress. The problem is when it becomes this eating disorder more than just a slight fear of food or worried about eating. It becomes an eating disorder when it leads to unintentional weight loss or nutrient deficiency.

And that’s when it’s more of a problem. It’s not just feeling a bit nervous about eating. It’s actually affecting your life and affecting your socializing. Affecting everything to do with the way that you eat and the way that you live your life. If you’re worried that that affects you, I would say start with your doctor but also there are particular therapists trained in eating disorders and things that can be really helpful if it resonates with you.

Um, have a little think about it. Listen to the episode about ARFID that I recorded previously and see if that might help.

How to gain weight with IBS

Okay, so I’ve got seven things that I think will help you to increase your body weight when you’re struggling with SIBO or with IBS.

1. Eat regularly

Firstly, regular meal times. So, eat regularly throughout the day and don’t skip any meals.

If you’re aiming to add calories to your diet one of the best things you can do is to add in a snack. Now, particularly in the SIBO world, people often want to try and regulate their migrating motor complex. That’s the small impulse that moves through our small intestine and And it helps to keep the small intestine clean.

Now, I also really promote to most people to have a little overnight fast that is 12 hours. So you’re giving your digestion a rest overnight, you’re not basically having a late night snack. But, when your body is empty, underweight and undernourished, I would say this is less important.

The most important thing for you to do is to restore a healthy weight and restore healthy nutrient intake. And you cannot do that if you’re fasting and you’re skipping meals.

Choosing your compromises and priorities

So, I know it’s a real challenge to think, well, what’s most important? Do I want to help get rid of my SIBO and help my small intestine cleaning? Or do I need to have another snack?

When you’re used to fasting, sometimes it feels very easy. And a lot of people I work with say that they just don’t even feel hungry. They don’t even want to eat. And so it’s easy for them to fast and it makes them feel better. So why should they stop?

Well, being in an underweight and undernourished body has got consequences. What we want to try and do, if you want to get your digestion sorted, is to get your entire body healthy, not just focusing on the gut.

One of the best ways of getting rid of SIBO, this overgrowth of bacteria in the small intestine, is to drink water. to be in a really healthy body with a strong immune system and you can’t do that if you are under nourished. Your body will struggle to fight off this bacterial infection in the small intestine.

Getting a stronger body and gaining weight can help IBS

We want to try and get your whole body strong and part of that is about eating regularly. So don’t worry about an overnight fast and don’t worry if you need to have a snack. I do recommend still having a discrete snack. (I don’t mean like a secret one, I mean discreet as in one episode of a snack, rather than nibbling on food all day.)

2. Include snacks every day

I still think having regular meals with a regular snack time, so you might have three meals and two snacks, or three meals and three snacks if you need it.

Gaining weight with IBS can be slow

If you’ve been, eating a reduced amount of food for a long period of time you may feel quick fullness that sometimes they call it postprandial fullness.

You will feel that very quickly as soon as you start to eat and feel like you just can’t eat anymore this is where having small regular meals can help in terms of getting the nutrients in and sometimes.

Snacks do not mean processed foods

You might hear me say, eat snacks, and think, oh well I don’t want to eat junk food.

But a snack doesn’t necessarily have to mean a packet of crisps or some biscuits. It could just mean a very small meal. So again, thinking about those balanced macros, protein, fats and carbs in each little.

3. Increase your fat intake

The third area is around increasing your fat content. Fats contain 9 calories per gram compared to 4 calories for protein and carbohydrates.

This means when you’re having more fat in your diet, it will give you more energy density and will overall help you to increase your calorie intake.

But some people really struggle with fat digestion, so build up slowly and see where your tolerance lies for increased oils and fats in your diet. If you can manage lactose containing foods, then things like full fat milk, hard cheeses can be really helpful and even playing around with adding cream to your diet, adding cream to different meals.

Try healthy fats

Some healthy plant based fats would be things like avocados, nuts, seeds, coconut oil and olives. Now, a lot of people will say, yeah, but they’re high FODMAP, I can’t eat those, I’m on a SIBO diet, or IBS people shouldn’t eat FODMAPs.

Well, not everyone with IBS or SIBO reacts this way. to all of these kind of fermentable starches. So while tolerance to foods definitely changes over time, it’s important to test out how you get on with small amounts of these things like nuts or avocado and build up from there. The other thing is oily fish, if you eat fish, are a great source of calories and the omega 3 also might help with anxiety and mood issues as well as skin conditions, so oily fish are a great choice.

The other thing you could consider would be taking a digestive enzyme which contains lipase and that will help you break your fats down as it hits the small intestine so may help you with absorbing and digesting the fats if you find that fatty foods are an issue for you.

4. Increase protein

Now, fish, as I mentioned just now, is a good source of protein as well, and that is my fourth tip, is about increasing your protein intake.

Protein is a building block for our muscles, and when we eat protein, it helps stimulate muscle growth. So, in order to gain weight, you probably need to increase your protein, and most people with IBS do. Do you find that they can digest protein quite well? So I’m talking about things like meats, fish, eggs, and these are really great sources of protein.

However, if you’re on a vegetarian diet, you can also include things like tofu, meat substitutes. And if you want my guide on low FODMAP versions of meat substitutes, you can go to the link in the show notes and I’ve got a download that you can access that.

Just trying to think about every meal and snack, does it contain some sort of protein. Nuts and nut butter. So you might be okay with peanut butter, for example, that is also a good source of fat. So very good to add to a piece of sourdough toast, maybe like a cracker that you feel okay with.

What about a protein shake?

These are really good ways to bulk up your calorie intake and a little bit of protein as well. Now, sometimes people ask, what about a protein shake? So I would say, um, You could consider adding a protein shake if you’re struggling to eat enough food. The goal is really to try and get your energy intake through food but where that’s not possible a protein shake could be helpful. And whey or soy based isolate protein shakes are normally good for people with IBS, however not everybody.

You can get low FODMAP vegan protein shakes if you need to navigate those. Now the fifth tip is about how to improve your appetite. I think I’m going to do another whole episode about this next week because there’s lots to say about it and I’m running out of time.

Consider a zinc deficiency

But just quickly, things that you could consider is whether you might have a zinc deficiency.

So zinc deficiency may cause a loss of appetite. If you never feel hungry, This could be a factor for you, but also want you to think about how to connect again with your appetite.

5. Connect to your appetite

Most people I work with have in some way suppressed their connection to their digestive system because they’ve had a lot of terrible stuff coming back from that.

All the messages have been about pain, uncomfortable gas and feeling sick. And so of course you’re trying to minimize that, but actually it can also stop you from feeling hunger. So what I work on with my clients is how to feel hunger again. What does it actually feel like for you? And when do you feel hunger?

Exercise can help your appetite

Also, although it’s a bit counterintuitive, sometimes doing more exercise can really stimulate your appetite. So don’t be afraid to do a little bit of weight training, try and build some muscle and then try and eat more in order to fuel your body for that exercise. So certainly thinking about your appetite before and after every meal, are you eating to the point of just taking the edge of your hunger?

Or are you eating to the point of being actually full? And when you want to increase your weight, you are going to need to feel full. And like I said, I know people with IBS can feel full very quickly. So we need to work on it and to track that over time. It’s not going to be something that you can get over quickly, but it is important to think about.

And how to try to connect with your appetite.

6. Don’t drink a lot of liquid right before a meal

The last two tips, number six is don’t drink at meal times. So I don’t mean you can’t have any liquid. It’s okay to sip on water to help your meal go down. But try not to drink a really big glass of water right before your meal, or don’t drink something as your meal.

eating loads because you’re just taking up space in your stomach and that may make you feel fuller more quickly which you don’t want because the liquid will go through you very quickly.

7. Get enough sleep and rest time

The final tip Is about getting better quality sleep and you may think what on earth has that got to do with gaining weight Well, partly being sleep deprived can interfere with our body’s repair processes So you’re building muscle overnight when you’re resting.

You’re not always just building muscle when you are doing the exercise Helping your body feel more rested can help reduce anxiety, which is really important when you’re starting to change your diet because of IBS symptoms. The gut brain connection is super, super important. So when we’re making dietary changes, You really want to actively try to focus on how to reduce down your anxiety levels.

That can be through getting better sleep. And if you’re someone who struggles with insomnia, yeah, that’s still going to be difficult, but maybe there’s some things you can do to prioritize getting better sleep, like nice wind down, stopping looking at your emails at 10 o’clock at night, having the room nice and cool, but also quiet.

Improve sleep hygiene

And if that’s not possible, using an eye mask, using earphones. Yeah. trying to block out the world for eight hours so you can try and feel better and your gut symptoms are less of a problem when you are less tired. They don’t obviously go away, but people feel more resilient when you are feeling more rested.

So, I know that is a lot that I’ve been through in this episode. I’m going to, I think, focus on appetite next week because that’s That is really key to making this work. So stay tuned for that next week. Okay. I’m going to leave it there. Thank you very much for listening to the inside knowledge for people with IBS.

Better digestion for everyone.

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