The ‘healthy’ habits that are actually harming your gut

Following rigid rules-based diets could be leading to digestive problems but experts say that moderation is key

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More than a million GP consultations in the UK every day are about digestive symptoms

Ten years ago, clinical dietitian Elaine McGowan thought she would be out of a job by 2022. Conversations around gut health were becoming commonplace and she hoped that people were understanding what a healthy diet looked like.

Instead, though, she’s busier than ever. McGowan and consultant gastroenterologist Prof Barbara Ryan, who have worked together for 13 years and joined forces as The Gut Experts in 2021, are seeing more cases than ever of people with poor gut health.

Many of them fall under a new category of digestive sufferer: the healthy eating fanatic. While they still see cases of people who have stereotypical poor gut health habits (not eating any fibre, eating too fast, drinking carbonated drinks and exercising vigorously after eating), around 20 per cent of the cases they see in their clinic in Dublin are well-intentioned people who, in a desire to eat more healthily, have created a gut health problem.

Typical dietary changes that are stirring up trouble include wheat and lactose restrictions, drastically increasing fibre intake and following vegan diets.

One young woman they helped had previously had no digestive trouble. It was when she started working out at the gym more regularly and making “healthy” diet changes that the problems started.

After listening to what her new diet was composed of, they discovered she was eating huge amounts of fructans and fructose; spinach and kale smoothies and prune and date bowls, the very kind of breakfast championed in attractive photographs on Instagram.

“It was actually causing her bloating symptoms because she was eating too much fruit and fibre,” says Ryan.

While it made sense to ensure she was eating fibre (a study by the British Dietetic Association showed that, for 60 per cent of Brits, their average intake of fibre was 18 grams a day – far less than the recommended 30g a day) going from a low level of fibre and increasing it dramatically can cause bloatedness and increase bowel frequency and diarrhoea.

“We’ve all been told to feed our gut bacteria, which is a great thing to do for your overall health, but if you’re taking loads of fibre, your gut bacteria can be singing but your gut can be screaming,” says McGowan.  

As The Gut Experts, they instead advocate an approach to increasing fibre that goes low and slow; they recommend a daily intake of 20g to start with.

Much of their advice is reassuringly about moderation and your own individual tolerance. Meat, red wine and dark chocolate get their thumbs up just as much as kefir and kimchi.

Ryan’s ears always prick up, she says, when she hears someone talking about “food rules”. “It can sometimes be difficult to know if someone has a digestive condition or a borderline eating disorder,” she says. “We’re seeing a lot more people eating very rigid diets and yet they are not feeling great. They’re cutting out more and more things because they’re trying to manage their gut symptoms but going about it the wrong way.”

What starts as trying to eat a little more healthily can lead to trying to eliminate sugars and eat less saturated fats. “That moves on quite quickly to more restrictive diet regimes, such as eliminating dairy and wheat.”

There’s little doubt though that we’re a nation suffering from our guts. More than a million GP consultations in the UK every day are about digestive symptoms. And a survey by digestion charity Guts UK found 43 per cent of adults experience digestive symptoms.

McGowan and Ryan’s first piece of advice is to consult your doctor if you’re experiencing digestive problems. However, they acknowledge that while GPs are good at spotting “red flag” symptoms – weight loss, sudden and acute changes in bowel habit, mouth ulcers, passing blood and getting up in the night with abdominal pain – they are often ill-equipped to help people suffering from irritable bowel syndrome (IBS).  

IBS is a common condition causing stomach cramps, bloating, diarrhoea and constipation.

“Western medicine is set up to sift out serious pathologies like cancer. So people who have non-life-threatening conditions like IBS, where it does affect your quality of life but not the longevity, can find it hard to access medical advice.”

And when people feel like their doctors aren’t listening to them, it drives them towards the internet.

“Teenagers are very influenced by social media and the perceived notion of what your body should look like,” says McGowan. “It’s normal to have a bit of bloating after a meal and for the stomach to distend a little bit. But that’s exaggerated on social media.”

They bemoan the demonisation of animal proteins. “I think if people want to do the plant-based thing for moral or ethical reasons, then OK, but if it’s for perceived health benefits? We personally don’t believe it’s a more healthy approach.”

Doing the sums on what you would need to eat to get your iron and calcium requirements from a purely vegan diet, McGowan says it worked out to be three bowls of kale, 18 tablespoons of lentils and 75 almonds a day.

“You have to really try really hard to meet all your nutritional requirements and that’s difficult to do without eating a lot of bloating foods,” says Ryan.

Legumes, the plant-based followers’ favourite, is problematic for gut sufferers when taken in large quantities.

If you are following a plant-based diet their advice is to take in smaller quantities of legumes (chick peas, lentils, peas etc). Use tinned ones and rinse them well. You can also try taking alpha-galactosidase, a digestive enzyme that breaks down the carbohydrates in beans into simpler sugars to make them easier to digest. “But really it’s about finding your individual tolerance,” says Ryan.

Tinned chickpeas are probably the easiest tolerated. And generally, she adds, so are meat substitutes tempeh, quorn, tofu. 

Animal proteins are well tolerated by the gut – particularly cheeses. “We’re not saying you need to eat a keto diet. It’s about balance,” says Ryan. “We’re all about moderation, but we live in a time of extremes.”

It is now estimated that at least 10 per cent of UK consumers are following a gluten free diet, despite only one per cent of the population being celiac.

A Sheffield University study from 2016 surveyed over 10,000 people in 2012, at which point 13 per cent were following a gluten free diet. A similar survey in 2015 revealed this had gone up to 33 per cent.

“Free from” aisles are a regular fixture of supermarkets today. The market for gluten free food is still growing and currently worth an estimated £835 million.

McGowan and Ryan worry that people are opting to restrict their diet, instead of adjusting amounts or exploring better quality gluten – high GI sliced white bread is Britain’s most-eaten bread, with £876 million worth of loaves sold in 2021.

“For most other people if you eat a big bowl of pasta, you might feel a bit bloated but that’s normal enough. It does not mean you have to cut it out completely, but you should eat a smaller amount if you want to feel comfortable,” says Ryan.

They also question how much better for the gut gluten free products are. A 2018 study by the University of Hertfordshire surveyed more than 1,700 products from five UK supermarket chains and found that gluten-free foods have more fat, salt and sugar than their gluten-including counterparts.

“People go down a strict road of ‘food rules’ where certain foods become the enemy, but there are no such rules. There isn’t one food that’s ‘bad’,” says Ryan.

Much maligned wheat, she asserts, actually feeds your good gut bacteria, helps your bowels move regularly and is very good for overall health.

Concerned by the amount of confusion they’ve seen in people who are trying to be healthy, they’ve written a book to share some of their knowledge.

What Every Woman Needs to Know About Her Gut is specifically aimed at women – IBS is three times more common in women than men – however much of their advice is applicable to men too.

They wonder what problems the restrictive diets they are seeing people follow are storing up for the future. One woman they helped in her late 30s had done an at-home food intolerance test in her 20s and had stopped eating dairy as a result. She went on to have three babies and then at the age of 38 was diagnosed with osteoporosis.

McGowan says all such diet restrictions should be made after consultations with a registered dietician. “Dairy protein allergy is extremely rare, affecting less than one per cent of the population. Lactose intolerance affects a small percentage. We can all still tolerate cheese, a certain amount of yogurt and milk.”

Their FLAT gut diet plan is all about finding your own tolerance levels of common triggers.

  • F is for the Fs; fibre, fructans (wheat based foods like pasta, breads and cereals) and fructose (fruit sugar).
  • L is for lactose, milk sugars.
  • A is for alliums, onions and garlic, which have particular potency for gut sufferers because they have a sugar chain similar to bread and pasta.
  • T is the mind and body connection. “Mental health is really important and stress plays a huge role. We all know that what’s going on in our head has a huge effect on what’s going on in our gut. Seventy per cent of serotonin is produced by gut bacteria. So what you eat has a huge effect on your mental health.”

Together they have a combined 50 years of experience working in gut health. “We’re not whippersnappers,” says Ryan, which is why they think they’re well placed to counter some of the spurious advice available on social media platforms.

When McGowan started her clinical dietitian career she would be constantly explaining how home-cooked favourites like cabbage were causing excess wind. Then she moved into the era of the takeaway, where clients would be troubled by the triggering garlic and onions that formed the base of dishes. Today she’s trying to educate healthy eaters who might be overdoing it on fermented foods and fibre.

“Our colleagues in the field are also seeing patients day in and out who are really confused by all the noise out there,” says McGowan. “There are a lot of conflicting dietary messages and poor quality information. We’re trying to help people navigate them as best we can.”

What Every Woman Needs to Know About Her Gut: The FLAT GUT Diet plan by Professor Barbara Ryan, MD and Elaine McGowan, RD (Sheldon Press). Pre-order now for £16.99 at books.telegraph.co.uk or call 0844 871 1514