Could your low-carb diet be wrecking your gut? Nutritionist explains why fiber is ESSENTIAL to beat belly bulge

Low carbohydrate diets have become a popular way for people to lose weight.

In the short term they’ve been shown to be safe and successful at reducing both body weight and body fat.

But is this way of eating healthy for your gut?

The typical foods that make up this diet are mostly fats and protein but limit foods that are high in fiber such as grains, pulses, fruits and vegetables.

Fiber is key to a healthy gut and beneficial bacteria rely on carbohydrates for energy using the types of fiber we are not able to digest.

There’s a good chance that if you don’t plan your low carbohydrate diet properly and think about including enough fiber then you may leave your gut to be overrun with harmful compounds and bad bacteria that can impact on digestion and other key areas of health.

Here, Rob Hobson, Head of Nutrition at Healthspan, explains how you can save your gut while following a low-carbohydrate weight loss diet.

What does a healthy gut mean?

Maintaining a healthy gut is bedrock to good nutrition as this is where most of the magic happens as food is broken down and nutrients are absorbed and assimilated.

Your gut also ensures that waste leaves the body efficiently and in steady transit.

When your gut isn’t working at its best you can encounter problems such as constipation, diarrhea or bloating, which are common complaints affecting most of us at some point.

An unhealthy gut could also be the result of a condition such as IBS or food intolerance including dairy.

How do we maintain a healthy gut?

What you choose to eat is essential to a well-functioning gut and one of the key players here is fiber.

This nutrient is a type of carbohydrate that occurs in a soluble form found in foods like oats and fruit, and also insoluble in foods such as seeds and bran.

The health benefits of fiber span much wider than simply digestion as research has shown a protective effect over bowel cancer and a reduction in the risk of heart disease, type 2 diabetes and weight gain from eating a diet rich in this nutrient.

The current recommendation for fiber has increased to 30g per day.

Currently the average intake of fiber in the UK is only about 60 percent of this target, which means most of us are not getting enough.

You can add fiber to your diet by eating mostly unprocessed and natural foods such as whole grains, vegetables, fruit, pulses, beans, lentils, nuts and seeds.

Gut bacteria

As well as eating enough fiber in your diet, a healthy gut also requires the activity of beneficial bacteria.

The body is full of bugs that make up one of the most complex ecosystems in the world.

The diversity of your microbiota regulates a healthy gut as bad bacteria are limited and tightly controlled by the good variety.

If your diet is unhealthy and rich in sugary or processed foods then there is a good chance that the good bacteria in your gut will become weakened, which can affect overall health and immunity (closely linked to gut bacteria) as you provide an all-you-can-eat buffet for bad bugs to thrive on.

Research has also highlighted how disturbances in gut flora may be associated with many other conditions such as IBS, allergies, obesity and even mental health conditions such as depression via the gut-brain axis.

The relationship between prebiotics and gut bacteria

Good bacteria have a symbiotic relationship with prebiotics found in the diet.

Prebiotic foods contain high amounts of indigestible fibers such as inulin and resistant starch that provide bacteria with the energy required to flourish.

Such foods include Jerusalem artichoke, bananas, asparagus, pulses as well as cooked and cooled potatoes and rice.

Many fermented foods also have prebiotic benefits such as sauerkraut and kimchi.

How does this all fit in with the low carbohydrate diet?

A low-carb diet is one that contains less than 50g of carbohydrate per day. Which is the equivalent of a couple of bread slices.

The diet contains mostly fat and protein and in the absence of carbohydrates the body switches to burning fat instead of glucose (carbohydrate).

The foods you can eat are meat, fish, eggs, certain low carbohydrate vegetables, nuts, seeds, high fat dairy and oils.

You can get enough fiber in your diet with vegetables and a very small serving of carbohydrate food but this means eating much more than the current average intake of four servings (National Diet and Nutrition Survey), which provides around 10g.

The vegetable choices may also seem limited by some people as sweeter vegetables like carrots and sweetcorn are out in favour of greens, celery, cucumber, fennel, tomato, cauliflower, onions and leeks, which may be a further challenge for some people.

What are the effects on gut bacteria?

A high fat and protein diet is not necessarily the issue as bacteria will find something to live on in the gut but the diversity of bacteria and their activity may change in the absence of carbohydrates.

Like us, bacteria prefer to live on carbohydrates (glucose) and from this they produce short chain fatty acids that are good for your gut.

Once carbohydrates are taken out of the diet, bacteria start to thrive on amino acids that make up proteins, which produces other compounds that are considered more poisonous than beneficial.

This shift in activity will be noticeable shortly after giving up carbohydrates as one or two weeks into this diet you will see and smell the difference and experience issues with your bowel movements.

Probiotics such as Healthspan Super50 Pro will help to add good bacteria into the gut but you need to add fiber and especially prebiotics to insure they get the right sort of ‘food’ required to produce compounds that help and not hinder the gut.

So how can you follow a low-carb diet and maintain a healthy gut?

It’s important if you are going to follow a low carbohydrate diet that you pile up on permitted vegetables to insure you get a good supply of fiber from your diet and keep your gut in the best heath possible.

Think about 10-a-day over five, which is the new advice from nutrition experts.

You should also include as many prebiotic foods as you can and some of these foods are great to add flavor to dishes such as fermented products including miso, kimchi and sauerkraut.

These highly flavorsome foods can also be a lifesaver if you’re bored of eating grilled chicken and vegetables every day!

Although carbohydrate foods are limited you may be able to include a small amount of pulses to make up your 50g of carbohydrates each day.

These foods are the richest source of fiber and even a couple of tablespoons can add one fifth of your daily intake.