The flat tummy myth: why bloating can be good for you – and when it’s time to worry

Yet another advert for an anti-bloating health supplement has popped up on my Instagram feed. Like many others, it shows a skinny young woman furrowing her brow while patting her distended midriff. The intended optics seem to be that a subscription to this tastefully packaged product would restore one’s ability to wear a crop top and leggings without cause to frown.

While anyone with irritable bowel syndrome (IBS) or any other inflammatory gut conditions knows that bloating and its frequent bedfellow distension can feel far more unpleasant than this ad looks, the array of anti-bloat powders and pills jostling for attention on social media has ballooned. As public understanding of the vast influence of gut health has grown, so has the global market for digestive supplements, which is projected to be worth £24.3bn within a decade. But how can consumers possibly know if any of these concoctions of herbal remedies, digestive enzymes and live microbes will have a positive, negative or zero effect on their tummies?

The flat tummy myth

Let’s start with the worried well – those who don’t have a debilitating condition and want to keep it that way. There is the distinct possibility that these adverts are making healthy people without flat stomachs feel as if they have a problem when they don’t. Marketers have long capitalised on dressing up normal bodily functions as problems – take the soap companies who invented the notions of body odour and vaginal douches.

“I don’t think human beings are meant to have flat tummies,” says Duane Mellor, a dietitian and lecturer at Aston University in Birmingham. “That’s social media messaging from people who have got time on their hands to sculpt their bodies. Humans come in all shapes and sizes – and all sorts of curvatures of the stomach.”

Some bloating after eating certain foods is normal and can even be a demonstration of a happy gut going about its business. Raw onions, under-ripe bananas and cold pasta, for example, present our digestive systems with resistant starch, which is a form of dietary fibre. The friendly microbes that colonise our guts ferment this fibre, which causes gas. “A little bit of wind is probably a good sign that the bacteria is fermenting away in your colon, producing chemicals that are good for your bowels and keeping them healthy,” says Mellor. “And it’s a sign that fibre is reaching the bowels, which lowers the risk of bowel cancer.”

Bloating is common and can have myriad causes, which muddies the water when seeking remedies. You don’t get diagnosed with bloating, says Mellor: “It’s a vague symptom, rather than a health condition, but it can represent one.”

The usual culprit

More often than not, however, bloating is caused by wind. “The digestive system isn’t designed to have a lot of air in it,” says Julie Thompson, a specialist gastroenterologist dietitian and the information manager at Guts UK, a digestive health charity. We often unwittingly fill ourselves with gas: every time we swallow; more so if we eat in a hurry, chew gum, smoke or consume fizzy drinks.

Constipation – a standard complication of a fibre-lacking western diet and a sedentary lifestyle – can compound the problem by blocking one of the body’s exits. As well as consuming enough fluid and fibre, says Mellor, “physical activity helps keep the bowels regular”.

An older woman exercising in her home gym
Staying active helps your digestive system work effectively. Photograph: MoMo Productions/Getty Images (posed by a model)

Food intolerances and excessive bacterial fermentation of food in the digestive tract can also generate extra gas. If this becomes a long‑term problem, a doctor can help identify food intolerances or bowel conditions. Some IBS patients are referred to a dietitian to supervise a reduction in triggers via a diet that cuts out Fodmaps, certain short-chain carbohydrates that are poorly absorbed by the small intestine and are prone to absorbing water and fermenting. This is an extreme, short-term measure; many of these foods are good sources of fibre and nutrients, so the idea is to reintroduce them methodically, one by one, once symptoms have stabilised.

When to see a doctor

Guts UK advises that you see your GP if bloating or distension persist for more than three weeks, especially if they are combined with additional “red flag symptoms”, says Thomson: “Unintentional weight loss, anaemia, a change in bowel habit, bloody poo, loss of appetite or an increased need to pee, the last one being a symptom of ovarian cancer; this always should be checked.”

Bloat and distension affect 90% of people with IBS, as well as those with functional dyspepsia (“similar to acid reflux disease”, says Thompson). There are plenty of rarer conditions that could cause abdominal bloating, too, while stress can trigger flare‑ups in many of them and cause irregular abdominal reflexes. When we eat, says Thompson, “the diaphragm normally relaxes and the abdominal wall muscles contract to help accommodate increased gut contents”. But sometimes the reflex reverses and does the opposite, causing distension and requiring specialist help to retrain it.

How to reduce wind

While kombucha can boost gut health, it can also exacerbate IBS
While kombucha can boost gut health, it can also exacerbate IBS. Photograph: LightFieldStudios/Getty Images/iStockphoto

It is normal to break wind up to 15 times a day, according to Guts UK. Burping happens between 15 and 20 times a day. If you are feeling excessively windy, you can try dietary alterations on your own, says Thompson, including “limiting the intake of commonly known gas-producing foods such as beans, brussels sprouts, cauliflower and sugar-free mints or chewing gum”. The final two often contain polyol sweeteners such as sorbitol, xylitol and maltitol, which can cause fermentation in the digestive tract, and even diarrhoea, if overconsumed.

Thompson says including oats in the diet can be helpful. There is also some evidence, she says, that a daily tablespoon of linseed can help with bloating; it doesn’t matter if it is ground or whole, but it needs to be taken with fluid. “It can take up to three months to be effective,” she says.

Eating fermented foods, such as kombucha and sauerkraut, can boost gut health, but these two in particular can backfire if you have IBS, because they are high in Fodmaps. Kimchi and miso paste are good low-Fodmap options.

Will health supplements help?

As for all the pills and powders in the online adverts, it is impossible to say how helpful they will be, even in the unlikely event that you have pinpointed the cause of your bloating. This is not to say that these products weren’t developed with the best will in the world, or that they don’t work for some people; there are plenty of glowing reviews and the placebo effect is real.

The evidence on probiotics improving gut symptoms such as bloating is sketchy. The many products vary widely, as does each person’s gut flora, so it is hard to draw conclusions. Generally, dietitians advise trying a probiotic for a month and stopping if there is no improvement in symptoms.

Peppermint oil
Peppermint oil is a medically approved remedy for symptoms of bloating and distension. Photograph: Yana Tatevosian/Getty Images

Clarissa Lenherr, a nutritional therapist, has noticed the proliferation in products advertised for bloating – and isn’t impressed. For starters, she says, “women are supposed to have a slightly extended area in the lower abdomen, because we have female sex organs”. There are other reasons a belly might start sticking out that are equally unlikely to be fixed by taking a pill: “It might be body fat, or someone might be around their period, or it might be endometriosis.” For most people, she says, “these pills are not going to work”.

A company called Arrae makes a pink bottle of tincture called Le Depuff, which contains “anti-inflammatory and detoxifying ingredients – red raspberry leaf, dandelion root, lemon balm, yellow dock and fennel seed” and is intended to “depuff and debloat”. These plant-based ingredients are unlikely to do you any harm, but watch out for ingredients made to sound more groundbreaking than they are. A powder called Gut Feel, by Rheal Superfoods, a company that secured investment on the BBC series Dragon’s Den, contains Actazin kiwi fruit extract, which it says supports digestion. A study showed that this extract can indeed increase stool frequency in healthy adults, but another study found that eating two green kiwis a day had a similar effect.

One plant-based remedy for which there is enough evidence to warrant medical approval is peppermint oil. “It can help with bloating and distension symptoms,” says Thompson. (There is no evidence for peppermint tea, or ginger, being effective, she says.) Peppermint oil is available over the counter at pharmacies, as is simethicone, an anti-flatulence medicine that combines small gas bubbles into bigger ones, making them easier to pass.

Digestive enzymes are another common feature of anti-bloat remedies, in which they are combined with probiotics and plant extracts. But Thompson says that non-prescription mixed digestive enzymes are usually at a much lower dose than doctors would prescribe. The only over-the-counter enzyme for which there is any evidence, says Thompson, is alpha-galactosidase. “This helps to digest galacto-oligosaccharides (GOS), which are found in beans and pulses – humans don’t possess the enzymes to digest GOS.”

What if it’s hormonal?

Hormones cannot be ignored as bloating culprits, especially in anyone using female hormone therapy. “People forget that our hormone receptors are all over our body, but especially in our gut,” says the GP and menopause specialist Louise Newson. Fluctuating hormone levels at any age can affect the digestive system, whether premenstrually or during perimenopause and menopause. Dropping oestrogen levels, for instance, can slow digestion.

“We see lots of women with bloating, heartburn and constipation, or even loose bowel movements,” says Newson. “We know it’s related because when we give them HRT for other symptoms, they come back and go: ‘Wow, my heartburn’s gone,’ or: ‘My bloating is gone.’ And we also know that our hormones affect our gut microbiome. If we’ve got good gut microbes, our bowel function is happier.”

Men experience bloating, too, with IBS diagnoses only slightly more prevalent in women than men, but studies have shown that more than twice as many women report bloating than men. This tends to be put down to regular hormonal changes, along with wombs and ovaries jostling for abdominal space.

Fluid retention is a whole other bloating category. It can occur as a result of dehydration, consuming too much salt and a host of more serious conditions. It is also associated with hormonal changes – particularly with changing progesterone levels, says Newson: “Our hormones are really important for every single function of our body. When there’s an alteration, it can affect the way our kidneys work and blood vessels can become more leaky.” This means water passes into nearby tissues.

Imbalances between the amounts of different hormones can cause bloating, too – and there is no one-size-fits-all solution. “We spend a lot of time working out the right dose of oestrogen, testosterone and progesterone, because everyone can respond quite differently,” says Newson. Any changes in hormone therapy dosage need three months to settle before being assessed for their effects on symptoms.

As menopause awareness has risen in recent years, the supplement market has been flooded with products promising to nix “menopause bloat”, but Newson favours treating the root cause first. “Balance your hormones, look at your diet, look at your lifestyle, look at your sleep, look at your movement,” she says. “And then let’s see how your bloating and anything else is. By that stage, the vast majority feel so much better.”