What happens to your body to cause bloating – and how to stop it

So, what exactly is happening in your body when bloating strikes? And more importantly, can you do anything about it? Let’s take a closer look.

What’s happening in your body when you bloat?

There are several physiological reasons why your stomach may feel like it’s ballooning, making it tempting to unbutton your trousers for relief. Typically, bloating can be caused by excess gas, fluid retention, or sluggish digestion.

• Gas build-up: Your digestive system is home to trillions of bacteria, mainly residing in the large intestine. Collectively known as the gut microbiota, these microbes play a crucial role in breaking down food and extracting nutrients. However, during this process they release gases – mainly hydrogen, methane and carbon dioxide. This bacterial fermentation can cause the gut to expand, resulting in that uncomfortable bloated feeling.
• Swallowed air: Whether you’re eating, drinking, or talking, you’re swallowing air. Eating too quickly, drinking through a straw, chewing gum, or even frequent sighing can increase the amount of air you gulp down. This air gets trapped and must escape somehow, either as burps or gas.
• Slower digestion: Food moving sluggishly through your digestive tract, whether due to stress, dehydration, certain medications or conditions such as IBS or constipation, can cause bloating. When food lingers longer in the gut, bacteria have more time to ferment, producing additional gas.
• Fluid retention: Hormonal changes, excessive salt intake, and dehydration can lead to water retention in the body. This can cause a feeling of puffiness, especially around the abdomen.

Is your bloating normal?

Occasional bloating is totally normal – particularly if you’ve just polished off a three-course meal or packed in lots of fibre from wholegrains and large amounts of fruit and veggies at once (more on this below). While bloating may not always feel great, it’s a sign that your gut microbes are being well fed.

Despite what the wellness industry might suggest, you don’t need an expensive anti-bloat pill, drink or gummy to 'fix' normal bloating. However, if bloating occurs most days, even after small meals, this is referred to as intermittent bloating and it’s worth getting it checked by your doctor. The same applies if you suffer from consistent bloating with other symptoms like pain, changes in bowel habits, unexplained weight loss or anaemia.

What’s causing your bloating?

Bloating is a complex mechanism with multiple triggers. Nine out of 10 people with IBS experience bloating and distention, and it is particularly common in those with constipation. Bloating can also be caused by indigestion, small intestinal bacteria overgrowth (SIBO), and gastroparesis (delayed gastric emptying). Endometriosis and menopause can also contribute.

Lifestyle and eating habits play a significant role. If you’re not chewing your food properly, eating too quickly, or consuming excessive amounts of alcohol or fizzy drinks, you could be exacerbating the problem. Even tight-fitted, high waisted clothes can be a culprit.

Does your food contain polyols? These are artificial sweeteners found in sugar-free drinks, sweets, gums and mints. They are poorly absorbed, causing bloating and diarrhoea. Maybe you are overdoing it with the fermented food, like kimchi, kombucha or kefir, or eating a lot of high-fibre and gas-producing foods like beans, garlic, onion, brussels sprouts, cauliflower and broccoli, which can all turn your gut into a wind farm.

Intolerances to dairy, gluten, or specific vegetables often cause bloating and other digestive complaints, due to the body struggling to digest the types of carbohydrates in them. Bloating can also be associated with gut dysbiosis, which is an imbalance of gut microbes, likely if your gut contains more potentially harmful bacteria vs beneficial.

Not sure what’s behind your bloating or where to start? Keeping a food and symptom diary can really help to spot patterns and identify possible triggers.

How to prevent bloating

The good news is, you don’t have to resign yourself to stretchy waistbands forever. Here are eight easy tweaks that can help ease bloating:

1. Eat slower. Life isn’t a competitive eating contest! Take your time, chew well, and you will be less prone to gulping air. Avoiding distractions will help too.
2. Ditch the fizzy drinks. Bubbles in your drink need to travel somewhere, and the first place they’re going is to the gut.
3. Stay hydrated, aiming for 1.5-2 litres of water a day. Water helps move things along, keeping digestion smooth. Try avoiding drinking while eating though, and have a sip after you’ve finished instead. Avoid using a straw too.
4. Increase fibre intake gradually. Fibre is the main fuel for your gut microbes and key for optimising gut health. But too much too quickly is a recipe for a bloated belly. If you are trying to eat more high-fibre foods, gradually introduce one or two high-fibre foods per week and see how your gut tolerates it. And remember to drink plenty of water.
5. Prioritise managing stress and getting good quality sleep. Your gut and brain are besties, but stress can cause disregulation and poor communication between them. This causes issues with gut motility (movement), slowing down digestion or speeding things up. Yoga, walking or even simple deep belly breathing can help. Poor sleep can also interfere with digestion and appetite-regulating hormones, making bloating more likely. Aim for 7-10 hours a night.
6. Increase your intake of soluble fibre. Add in more oats, chia seeds or linseeds. There is evidence that linseeds (1-2 tbsp with a cup of water a day) may be effective in reducing bloating, but this could take several weeks to take effect.
7. Support your beneficial gut bugs. Small daily amounts of fermented foods such as yogurt, kefir, kimchi and sauerkraut, and prebiotics from plant-based foods like wholegrains, oats, almonds, fruits and vegetables can help keep your gut happy.
8. Go for a 10- to 15-minute walk after meals. A study in 2021 found that doing this reduced bloating along with fullness, wind and discomfort.

Can you banish bloating forever?

Bloating often occurs while your body is digesting food, and it’s a normal part of the process. Yet if bloating is persistent and uncomfortable, it might be necessary to look at your diet and overall health as there could be an underlying condition. Making some small changes can help banish the bloat, but it’s never going to disappear completely. Just remember, a little bloating also means your gut bacteria are having a good ol’ time, so try to celebrate that rather than worrying too much.