7 science-backed things to know about bloating

1. What actually is bloating?

In simple terms, bloating is a feeling of increased pressure in your intestine, sometimes with a visible swelling (what you might call a ‘food baby’). Two of the most common causes are built-up pressure from the sheer volume of food or fluid you’ve eaten, and gas produced by the trillions of bacteria in your gut (your gut microbiome) when you eat large amounts of certain high-fibre foods. These might include legumes (such as chickpeas), veggies (such as cauliflower) and fruit (such as cherries).

This increase in gut content stretches the intestine, giving you a bloated feeling. Now, a little bloating after a high-fibre meal is often a good sign: it shows well-fed gut microbes doing their job. As you may have experienced yourself, everyone’s gut is different. You can eat and drink exactly the same as someone else at the table and have a completely different reaction. This is something our research team at King’s College London has been investigating, and it explains why everyone has their own unique set of bloating triggers (more on those below).

2. And when should I be worried about it?

Whether to investigate your bloating depends on how much it affects you, physically and emotionally. Is it getting in the way of your quality of life? If the answer is yes (or you have any of the red flags below*), it’s worth a visit to your GP to rule out other causes, like coeliac disease. Once you have the all-clear, the good news is that the science has come a long way, and we now know that most bloating can be managed with diet and lifestyle strategies. Gone are the days of suffering in silence.

3. Know your triggers

From my research at King’s and 17 years working in gut health, I’ve found that most people’s bloating is triggered by a combination of food and lifestyle factors. Outside of specific food intolerances, like lactose (milk sugar), it’s rarely one food alone that causes bloating. It’s more likely you’re sensitive to a blend of foods. So if you’ve cut out the one food you suspect and you’re still bloated, this may be why. But here’s the important thing: you can train your gut to enjoy many of your trigger foods, because as we’ll cover below, cutting out foods long term can often do more harm than good.

Many people are also surprised to hear that some triggers can even make you more likely to bloat when you eat other foods. Take salt, for example. Research suggests that higher salt intake can change your gut microbiome, and over time, it may change how your body metabolises different foods. That means a higher-salt diet may be making your gut more vulnerable to bloating, while also making salt itself harder to spot as a contributing factor. It’s a good reminder that your triggers aren’t always the foods you’d expect.

I’ve seen these kinds of complexities trip people up time and time again in clinic, and they led me to develop my 3T method and Bloating Masterclass. More on that below.

4. Restrictive eating is not a solid long-term strategy

You may have been told that foods like lentils, or components like gluten, are the biggest bloating culprits and that you should cut them out. But not only can cutting out wholesome foods affect your overall gut health (and so your likelihood of bloating long term), it can actually make you more sensitive to foods over time. This is also why many people find their gut is more sensitive once they reintroduce foods after an extended fast. So cutting out nutritious foods shouldn’t be your automatic first move.

5. Prebiotics might do more harm than good

Prebiotics aren’t only unproven to help bloating; they can also trigger it. Why? Prebiotics are like fertiliser for your ‘good’ gut bacteria. But that means they tend to ferment very quickly in your intestine, creating pockets of gas. How you react depends on the type and dose, and on your own gut. For some people it’s fine, but if you have a sensitive gut and can’t move the gas along effectively, it gets trapped and triggers bloating. It’s a good example of why it pays to check the evidence before buying supplements.

6. Where your bloating is located tells you a lot

Did you know that where and how you bloat offers important clues about your triggers? If you mostly bloat in your mid-abdomen (around your belly button), for example, it’s likely connected to what you eat rather than how you eat. So, the most effective strategies for bloating in the middle of your stomach tend to be different from those for upper-abdominal bloating. To be clear, it’s not the whole story on its own, but it’s a useful clue.