Does eating fewer than three meals a day affect your gut health?

Breakfast, lunch and dinner are staple parts of nearly everyone's day. For as long as we can remember, having three square meals has been the norm – but times are changing.

According to the Waitrose 2023 Food and Drink Report, meals are out and snacks are in. The retailer surveyed its shoppers and found that the vast majority of respondents (95%) snack between meals.

But having a snack two or three times a day is also changing the way some are eating. Almost a third (30%) of respondents said they have just two meals a day, while snacks replace the third meal. A further one in 10 said they eat just one meal, preferring to graze on snacks throughout the rest of the day.

Much of this new eating pattern is fuelled by working from home. Waitrose found that 43% of people who work from home say they often snack throughout the day. The most popular time of day to have a snack is after 3pm (43%), which suggests people may be snacking instead of having a proper lunch.

We might think that eating three meals a day is something humans have always done. In reality, food historians say it wasn't until the 18th century that this dining pattern became the norm in the UK.

The idea that breakfast was the most important meal of the day started being promoted in the 1920s and 1930s, according to the BBC, while lunch was never really a thing until the Industrial Revolution.

In fact, having three meals a day might not be the best way to maintain our health, including our gut health. Research shows that eating fewer meals and fasting for longer than overnight can be good for you.

Are three square meals a day optimal for gut health?

The short answer is: no. The number of meals you eat a day doesn’t determine how good your gut health is going to be – instead, what you eat is far more important.

Isabela Ramos, nutritionist at at-home testing company MyHealthChecked, tells Yahoo UK: "The influence of meal frequency on gut health varies between individuals. It’s crucial to prioritise the quality and diversity of the diet rather than strictly adhering to a specific number of meals.

"A balanced diet that includes prebiotic-rich foods fosters a healthy gut microbiome. Consuming whole foods like fruits, vegetables, and whole grains supports the growth of beneficial bacteria, promoting overall gut wellbeing."

Liz Cooper, nutritionist at Bio-Kult, adds: "Our beneficial gut bugs like to feed on prebiotic fibre rich foods, whilst low fibre, sugary diets can encourage the growth of more pathogenic species [which can produce disease]. The gut microbiome plays an instrumental role in regulating the immune system (70% of which resides in the gut) and dysbiosis (an imbalance of the gut microbes) is implicated in many chronic inflammatory diseases.

"Research has also demonstrated a connection between the gut microbiome and the brain, known as the gut-brain axis, with the potential to modify mood, cognition and brain-function."

What happens if you don’t have three meals a day?

Cooper says it can be beneficial to have less than three meals a day, particularly because we no longer work the same way we did during the Industrial Revolution – which is when the eating pattern became ingrained in society.

"People would eat before they started work, have more food when they took a break at midday and would eat their main meal after work in the early evening," she explains. "So we actually evolved to eat less often than we do now and ancient wisdom actually encourages eating less.

"Studies indicate that fasting may improve the health of the gut lining, modulate the composition of bacteria in the gut and increase the production of beneficial bacterial metabolites, which could potentially explain some of the associated metabolic benefits, such as blood pressure reduction and weight loss. Having said that, fasting may not be for everyone, so it’s important to check with a health practitioner before undertaking a fasting programme."

Ramos adds: "Fasting may [also] enhance microbial diversity and contribute to the overall resilience of the gut microbiome. While the specific effects depend on individual factors, such as overall diet quality and lifestyle, intermittent fasting could potentially offer positive influences on gut health."

Can snacking negatively affect your gut health?

While we don't necessarily have to eat three meals a day to maintain a healthy gut, it's important to be mindful about the frequency of our snacking and the type of snacks we’re reaching for.

Cooper explains that allowing your digestive system time to rest between meals and snacking is vital to keep it healthy. "The stomach and small intestine contain something called the migrating motor complex, or MMC for short," she says. "The MMC involves wave-like muscle contractions of the bowel wall, which are necessary for the propulsion of food and dead cells through the gut.

"It goes through four phases, which take approximately 130 minutes and when these contractions are slow or irregular, or when the cycle is interrupted, food can remain in the small intestine for longer than is necessary. This gives bacteria in the small intestine time to ferment the food, potentially causing gas and bloating and allowing the growth of more bacteria."

Snacks should include things like fibre-rich fruits, vegetables and yogurt, which contain prebiotics, Ramos recommends. She adds that snacking on processed or low-nutrient foods "may disrupt the balance in the gut microbiome", so it’s important to make wholesome snack choices.

Along with eating the amount your body needs, the Eatwell Guide shows that to have a healthy, balanced diet, you should try to:

• eat at least five portions of a variety of fruit and vege every day

• base meals on higher fibre starchy foods like potatoes, bread, rice or pasta

• have some dairy or dairy alternatives

• eat some beans, pulses, fish, eggs, meat or other protein

• choose unsaturated oils and spreads, and eat them in small amounts

• drink six to eight glasses of fluids a day

Consult a medical professional before making any big changes to your diet.

Watch: What Happens To Your Body When You Eat a Late-Night Snack Every Day

Read more about gut health:

The one key nutrient to improve your gut health—here's how to get more of it (Yahoo Life UK, 4-min read)

Could the 'world's smelliest cheese' be good for your gut health? (Yahoo Life UK, 4-min read)

The best and worst foods to eat this Christmas for your gut health (Yahoo Life UK, 6-min read)