What causes stomach bloating?

What causes stomach bloating?

 Not chewing properly

Let me tell you something useful.

Digestion doesn’t start in your stomach. 

Digestion starts in your mouth.



It was a surprise to me too!

Before I learned that simple fact I only chewed my food long enough to enjoy it -and make it small enough to swallow. 

I didn’t think it mattered how long or how well I chewed for, because I didn’t realise chewing had any impact on my digestion.

But believe me, it does.

Here’s why.

When you chew, your teeth break the food down and mix it with your saliva. 

Your saliva isn’t just there to help food slip down easily. (Another revelation to me!) 

Saliva contains digestive enzymes – chemicals designed to breakdown carbohydrates in to simple sugars.

If  you don’t chew well the undigested carbohydrates become food for bacteria in your gut. 

This leads to fermentation. 

Fermentation leads to gas. 

And gas leads to bloating.

What to do – 

First up – the next time you eat pay attention to how well you chew your food. 

Chewing is something that you’ve done automatically for years. 

But you may not chew thoroughly enough. 

So ask yourself … 

Do you chew until the food in your mouth is broken down? 

Or do you chew briefly and swallow chunks of food? 

Swallow before the the saliva has done its job and you’re likely to begin to feel gassy and bloated within a few hours.

The solution –

Take small mouthfuls. 

Chew food really well. Chew longer than feels normal. Remember your aim is to change a habit of a lifetime so it can feel strange at first. 

Of course the length of time you chew for will depend on what you eat – but only swallow when the food is broken down in to a paste. 

Some food is already a paste before you start to eat so, although it doesn’t need to be physically broken down by your teeth, it does still need to be chemically broken down by the enzymes in your saliva.

So. Chew well. And keep the food in your mouth long enough to allow your saliva to do its thing!

Because the longer you chew – and the longer you keep the food in your mouth – the better your digestion will be. 

And the less likely you are to bloat.

Eating too quickly

When you rush your meals your breathing quickens, your upper body becomes tense and your nervous system assumes you’re under threat – even though you’re not. Digestion is not required to get you out of a dangerous situation (even an imaginary one) so when the body is in a state of stress and tension digestion is impaired. This applies to any form of stress – not just the stress that comes when you eat quickly.

The solution –

Make time to eat. Always sit down – ideally at a table. If you’ve been in a rush before your meal take a moment before you start to eat to relax. Pause. Smile. Soften your shoulders. Soften your belly. Breathe out deeply. Be thankful for the food in front of you. Then eat slowly and mindfully. Put cutlery down between mouthfuls. Focus on the sensations in your mouth. Enjoy!


Under-hydration leads to water-retention. Water retained around the abdomen will cause you to swell up and look bloated. You also need water to produce saliva and other digestive juices.

The solution –

Drink plenty of clean fresh water. Cut out diuretic drinks such as coffee, tea, alcohol, soda, fizzy drinks and fruit juices. Avoid processed foods high in sodium. Eat plenty of water-holding salads and vegetables. Choose water-holding grains over dry ones. E.g. well-cooked oats rather than dry bran flakes. Well-soaked meusli rather than dry meusli. Seeds and dry fruit should be soaked – not eaten dry. Some environments are particularly drying. If you work in a warm or air-conditioned atmosphere you need to compensate with extra water. Stress is dehydrating too. So is talking.


Stress affects digestion and can cause bloating. It doesn’t matter whether the stress is big or small, due to life situations, your environment or your diet.

The solution –

Be aware that stress comes in many forms. Lack of sleep, food sensitivities, adrenaline sports, noise pollution, caffeine, sugar, quick eating, perfectionism, other people’s demands … to name a few. Some stressors you can work to reduce or avoid. Some you can’t. But you can work to counteract their effect. Yoga, aromatherapy oils, massage, meditation, walking, laughing, being in nature, reading a good book, listening to music that lifts your spirit, being with people you love … do anything that helps you feel good.

Caffeine and sugar

Caffeine and sugar create a stress response in the body. Stress is not good for digestion – (see above).

The solution –

This one’s simple. Cut out foods with added sugar. And don’t drink tea, coffee, energy drinks and caffeinated soda/soft drinks. Chocolate contains caffeine and sugar. A double whammy! Avoid it. If you had a strong emotional reaction to that suggestion – the chances are you need to avoid chocolate more than someone who can take it or leave it. Attachment to certain foods or drinks can indicate an under-lying (or obvious) sensitivity.

Lack of bowel flora

Low bowel flora leads to fermentation in the gut and issues with digestion such as bloating, gas and diarrhoea. Low bowel flora also affects the nervous system, the immune system and can cause cravings for sugary foods and refined carbohydrates.

The solution –

Reduce your intake of refined carbohydrates and sugary foods as you work to repopulate the gut with a good probiotic. The one I recommend is VSL 3. Available on Amazon UK and USA. If you don’t live in those areas then look online or visit a good local health food store to find the best probiotic available to you. Look for a high strength and a broad spectrum of bacteria. Symprove also has a good reputation – although I’ve not tried it myself. Good probiotics are expensive – but an investment in your health. You can also take naturally probiotic foods such as fermented cabbage (yum!) which is cheap and easy to make at home.

Food sensitivity

Food sensitivity and intolerances create stress in the digestive system and can lead to bloating from gas or fluid retention. This includes gluten sensitivity and coeliac disease.

The solution –

Ask your GP to check for issues with gluten. Be aware you could be fine with gluten but still react to the fermentable sugars in wheat. Have a Food Intolerance Test carried out. If that’s not available to you do an elimination diet for a number of weeks to see if you feel better. The most common foods that cause bloating are wheat and dairy products (milk, cheese, yoghurt and cream) – and lactose which is found in a high number of processed foods. After wheat and dairy the next suspects are onions, sweet fruits such as apples and grapes, refined sugar, yeast, caffeine, beans and pulses. Keep a food diary to note any changes in your bloating and bowel function not just when you take foods out but when you put them back in after the elimination period. If bloating is food related it is often the result of more than one thing so you need to eliminate the possible culprits at the same time. When the bloating stops reintroduce them one at at time and note your gut’s reactions.

Lack of movement

A sedentary lifestyle can lead to a sluggish lymphatic system causing a build up of fluid in the abdomen. Lack of movement can also lead to a congested bowel, hormonal issues and stress-related digestive problems.

The solution –

You don’t need to go to a gym to move your body. Find ways each day to be as active as possible. Walk some of the way to work, take the stairs, dance around your kitchen, do vigorous housework, go for a walk after lunch and dinner, get a mini trampoline and bounce on it a few times a day … you get the idea. High intensity is better than slow and steady. A fast 10 minute walk a few times a day is more beneficial to your fitness than 10,000 steps a day at a slow or moderate pace – which takes forever and is impossible for many people to achieve. Your aim is simply to move as much as you can – doesn’t matter how you do it.

Junk foods

A diet high in poor quality processed food is usually high in bad fats, sugars, salt, preservatives, colourings and flavour-enhancers. This type of food is alien to your body. It can be difficult to digest and cause a bloated belly and other digestive issues such as reflux, constipation and diarrhoea.

The solution –

Be mindful of what you put in to your body. Read labels. Not the marketing blurb on the front. It’s the list of ingredients on the back you want to pay attention to. If you don’t know what they are – there’s a good chance your body hasn’t evolved to eat them. Natural, unprocessed food is best.

Fermentable carbohydrates

Some natural carbohydrates are high in fermentable sugars and alcohols which, if you have an imbalance of gut flora, could cause you to bloat up and give you gas and diarrhoea. They are known as FODMAPs. You’ll find a list online.

The solution –

Keep FODMAPs low in your diet. If you avoid wheat and lactose you dramatically reduce the level of FODMAPs in your diet and other fermentable carbohydrates become less of an issue. Once you have your gut flora rebalanced FODMAPs can be gradually increased.

Synthetic sweeteners

Synthetic sweeteners can cause inflammation and feed any yeast present in the bowel – leading to gas and bloating. Some have a laxative effect.

The solution –

Avoid synthetic sweeteners. Your body doesn’t have a clue what to do with them. Some products which contain them, such as sugar-free gum, will warn of their laxative effect on the packet – in lettering so small you would never notice it. Another good reason for always reading labels!

Chewing gum

Chewing gum confuses the digestive system and can cause indigestion, heartburn or refllux.  Sugar-free gum contains synthetic sweeteners that can cause bloating and have a laxative effect.

The solution –

I wouldn’t recommend it but if you do decide to chew gum do so only for a short time just after you eat. And make sure it doesn’t contain Aspartame. It is linked with a wide range of health issues which includes inflammation in the bowel. Although some of the issues linked to Aspartame are so serious (if you consume it regularly) inflammation in the bowel should be the least of your worries.

Vitamin and mineral deficiencies

Low levels of essential vitamins and minerals such as Vitamin D and Magnesium are linked with bloating and IBS. Cramping, diarrhoea or constipation can be a sign of low magnesium levels.

The solution –

Eat a diet high in whole-foods with plenty of oily fish and green vegetables. However, even if you do you could still benefit from supplements. If you don’t get much sunlight Vitamin D is essential. And it’s difficult to get enough Magnesium – even in the healthiest diet. Modern farming techniques have left the soil depleted. If there’s no magnesium in the soil – there’s no magnesium in your veg. So a Magnesium supplement will keep you topped up.

Something serious

Persistent bloating is one of the signs of ovarian cancer. If you have been bloated daily for over 3 weeks it’s worth getting checked. Especially if you feel full quickly after you eat a small amount.

The solution –

Get checked by your GP or healthcare professional. Most people who get bloated or have issues with constipation. gas or diarrhoea don’t have anything serious – but some do. Ovarian cancer is treatable if picked up early.


Bugs in your tum! Bacterial or parasitic infections. If this is the issue then any of the above triggers will only make things worse. Gurgling noises in your gut, low energy, thrush, brain fog and sugar cravings are some of the signs of excessive yeast. Helicobacter pylori is a bacteria that causes heartburn, bloating, burping, abdominal pain and at times nausea. H pylori can lead to stomach ulcers.

The solution –

Arrange to have a stool test carried out by your healthcare professional to check for parasites. Or have a blood test if you suspect Helicobacter pylori. This is treated by a short course of antibiotics. Antibiotics destroy gut flora so always follow with a good quality probiotic. Cut out added sugar. Reduce sweet fruits and starchy carbohydrates. Take a good probiotic to balance gut flora (even if you don’t need antibiotics). Reduce stress (see above). Drink plenty of water. Take natural anti-fungals such as cinnamon and coconut oil.


There are loads of nerve-endings in your gut which can react to stress or hold on to unprocessed emotions. Bloating can be due to grief, anger or fear – or any emotion that you’ve had to ‘swallow’ down or felt ‘gutted’ by. Indigestion, nausea or heartburn can be linked to something that you ‘can’t stomach’ – a long or short term life situation that’s been difficult to cope with. Some people are able to expressive their emotions and process life’s difficulties quickly. But if that’s not you – you could be holding the emotions in your belly and experience bloating, gas, constipation or diarrhoea as a result.

The solution –

There are various ways that you can help yourself to process emotions. Daily gratitude helps. Or find ways to be charitable to others and to yourself. And give yourself permission to be vulnerable and imperfect. If you feel that you would like help to move forward you could find a registered therapist who offers Cognitive Behavioural Therapy, Hypnotherapy, Emotional Freedom Technique, Brain-Spotting or The Comprehensive Resource Model – to name a few. There are other techniques that can help. Find what fits you. Or you could write freely in a journal each morning about anything that comes in to your head to help to shift emotions.

Food combinations

The foods you combine – and the order you eat them in – can result in bloating and gas. Fruit eaten after a meal can cause fermentation in the gut. The digestive system doesn’t work so well in the evening so if you eat a heavy or complicated dinner (especially with raw food such as salads and fruit) you could find it a struggle to digest.

The solution – 

Eat fruit on an empty stomach – never after a meal. Keep salad and fruit to the start or middle of the day – never after 4 pm. Don’t drink fruit juice with a meal. Definitely not with dinner. Some people have better digestion if they follow a Food Combining Diet and don’t eat carbohydrates and protein at the same meal. So meat, fish, cheese, nuts and eggs with non starchy vegetables at one meal. Then rice, pasta, potatoes or other starchy vegetable with salad and non-starchy vegetables at another meal.