What happens to your gut if you don’t eat fruits and vegetables?

Gut health woman eating bowl of fruit veg. (Getty Images)
Does your diet lack in fruit and veg? Your gut could be bearing the brunt. (Getty Images)

We're starting to hear more and more about how important it is to have a healthy gut, dependent on the type of food we fuel it with.

And with getting enough fruit and veg a key part of this, it might prove useful to understand what could happen to your gut without any of your five a day, to see just how important it is.

So, for comparison's sake, we consult the experts on exactly what would happen to your gut if it was starved of fruit and veg, the knock-on health consequences, whether damage can be reversed and how much fruit and veg makes for a 'healthy' gut.

What happens to your gut without fruit and veg?

felt intestine and bacterias growht
Starving a gut of fruit and veg has negative implications on all areas of your health. (Getty Images)

"It is important to include a variety of fruits and vegetables in your diet to ensure you get a wide range of phytonutrients and dietary fibre, which is crucial for healthy digestion," says Charlotte Fraser, naturopathic nutritionist at Kaylo.

"Without sufficient fibre, you may experience digestive discomforts like constipation and irregular bowel movements."

Technically speaking, not eating any fruit and veg will alter your actual gut microbiota (microbes, or bacteria, that are both helpful and potentially harmful) – and not for the better.

"Fruits and vegetables contain prebiotic fibres [e.g. apples, blueberries, asparagus, onions, chicory, cold potato and fennel] that nourish our beneficial gut bacteria," Fraser emphasises.

"Without them, harmful bacteria can thrive, leading to imbalances in gut microbiota causing issues such as IBS, inflammation, fatigue, sluggishness, reduced energy, pH imbalances, issues with enzyme and protein production."

A closer look at mental and physical effects

Effects of diet on gut health. (Frontiers/BioRender)

On more knock-on effects of a gut starved of fruit and veg, Alistair Richardson, nutritionist at Kaylo, explains, "Changes in gut microbiota can also lead to microbiome dysbiosis, which is essentially dysregulation of the gut microbiome. This impacts hormone regulation which affects mood and often leads to mental health disorders such as depression.

"Imbalances in gut microbiota also impact metabolism, thyroid function, adrenal function as well as hormones, meaning it becomes more difficult to regulate your energy levels and mood changes.

"Some 95% – 97% of serotonin receptors live in your gut, so if your gut isn’t happy, you won’t feel happy."

As well as affecting digestion, Fraser says a gut not fed any fruit and veg can lead to nutritional deficiencies and an increased risk of disease long-term. "A diet lacking in fruits and vegetables is low in essential vitamins, minerals, and phytonutrients, increasing the risk of chronic diseases."

Plus, it can compromise your immune function. "Fruits and vegetables rich in vitamins C and E and antioxidants support immune function by stimulating the activity of white blood cells. Without these, one is more prone to infections such as pneumonia and diseases such as scurvy," the expert adds.

Can we reverse damage to our gut from not eating fruit and veg?

"Yes you can, but it’s not a one-day-wonder," says Aletta Sørensen, registered nutritional therapist at Harley Row Clinic.

"If you suddenly start eating fruit and veg after many years of none at all, you will not instantly feel better – in fact you might feel worse at first as your body is not used to digesting fibre. Some people may feel better in a few months, and some may take longer. It depends on each person’s situation and what condition the gut was in before."

She also points out, "It’s important to have variety, and not eat the same thing all the time. For example, someone who eats broccoli everyday has technically eaten a lot of vegetables in their life – but they will not have a healthy gut or immune system, because it is a variety of plants that the gut needs in order to thrive."

How much fruit and veg does a healthy gut require?

Female hands are preparing yogurt with chia and blueberries for good digestion, functioning of gastrointestinal tract. Summer berries, nuts, fruits, dairy products on table. Healthy food concept.
Variety is key. (Getty Images)

"For a diverse and balanced diet, aim for at least seven plants a day and 30 different varieties a week including vegetables, fruits, legumes, nuts, seeds, and whole grains. Opt for a variety of colours, and prioritise seasonal, organic, and local options," says Fraser. "Frozen vegetables are also nutritious alternatives. I recommend three-four vegetables for every one-two fruits in terms of ratio/balance during the day to keep sugar levels down."

Richardson adds, "I recommend also trying your best to eat seasonal fruit and vegetables. These will be more nutrient and vitamin dense."

Tim Spector is known as the man behind the '30 plants a week' suggestion, to maintain a healthy gut microbiome. Here he shares why we should be eating more than just the recommended '5 A Day', and exactly how to achieve it.

What happens to your gut with enough fruit and veg?

On the flip side of going cold turkey, here's a reminder of the benefits of eating enough fruit and veg on your gut and subsequent overall health, according to Fraser.

  • Improved digestion: Their fibre promotes regular bowel movements and prevents digestive issues like IBS and inflammatory bowel disease

  • Balanced gut microbiota: Prebiotic fibres feed beneficial gut bacteria, enhancing gut health and immune function

  • Reduced inflammation: Anti-inflammatory compounds in many fruits and vegetables can lower the risk of chronic inflammatory conditions

  • Lowered risk of chronic diseases: Their nutrients protect against autoimmune diseases, heart disease, cancer, and diabetes

  • Contribute to daily water in-take: Think how much water there is in a cucumber or courgette for instance – dehydration is a common contributor to many gut health problems

Always consult a doctor before making changes to your diet and about the best nutrition for you personally.

Evidence for the occurrence of fruit and vegetable bacteria in the human gut. (Taylor & Francis Online/BioRender)

Watch: Five reasons why you should prioritise gut health