We know that gut health is a vital part of our overall health and wellbeing. What we eat and how our bodies process it is crucial for a healthy functioning digestive system, and the benefits of this are far-reaching. From improved mental health to better energy and sleep, it seems there is little that isn’t affected by our gut health. It makes sense, then, to focus on the food we’re nourishing ourselves with. 

It’s less rare, however, to consider what happens in our bodies once we’ve eaten, but researchers believe that the journey our food goes on inside our body is as vital a part of our gut health story as what we’re consuming in the first place. 

In particular, they’re interested in how long it takes food to make its way from our mouths to, well… the moment it’s eliminated from the body as waste, also known as gut transit time. But what is this, and why is it so crucial? 

Put simply, gut transit time is the time our food spends in our body. 

“Gut transit time is the length of time it takes your body to digest the food you’ve eaten, so it’s everything from chewing to pooing,” says Gemma Stuart, gut health expert and founder of Gut Wealth. “It’s how long it typically takes for your body to break down the food you eat, absorb the nutrients, and then pass out the remaining waste that your body doesn’t need. Every gut is different, and the time taken can vary from person to person.”

On average, food takes between 24 and 48 hours to pass through a 30-foot digestive tract, and being able to identify how long or short our gut transit times are can give us a clue as to the state of our overall health. “Numerous important processes occur in the digestive tract that are essential for our health,” says Lorraine Demetriou, nutritional therapist and scientific advisor at Nutri Advanced. “It’s where food is broken down, nutrients are absorbed and waste is collected and prepared for elimination. We need enzymes, hormones, systems and cells to be functioning optimally for this digestive journey.”

As we’ve touched on above, the experts believe that our gut transit times can reveal a lot about our overall health. Too long, and we can be prone to constipation, higher visceral fat levels and more. A speedy transit, on the other hand, can be a sign of a poor microbiome.

“Through our research at Zoe, we discovered that gut transit time can be a more reliable indicator of gut health than commonly used measures like stool consistency, frequency or even the Bristol stool scale,” says Professor Sarah Berry, chief scientist at Zoe. “Our study revealed that individuals with longer gut transit times tended to have less frequent bowel movements and were more likely to experience constipation, have less favourable responses to food and more visceral fat, which accumulates deep within the abdomen. However, it’s important to note that it’s not just about speed. Individuals with the fastest transit times, which can indicate diarrhoea, often had less healthy gut microbiomes. This underscores the complexity of the relationship between gut health and transit time.”

On average, gut transit time is 24 to 48 hours but can vary from 12 to 72 hours, according to Nishtha Patel, a nutritional therapist and gut health expert. “Transit times will depend on factors like diet, hydration, gut microbiome, stress and physical activity,” she tells Strong Women. “Faster transit times (less than 12 hours) may indicate issues like malabsorption, diarrhoea or hyperactive digestion. Slower transit times (longer than 72 hours) may suggest constipation, sluggish digestion or a lack of fibre and hydration.”

And it’s not just physical health that’s affected. Additionally, transit times can impact the gut-brain axis, influencing our mental health too. 

“We know that there’s a strong gut-brain connection – around 90% of serotonin, our ‘feel-good’ neurotransmitter, is produced in the gut,” explains women’s health nutritionist GQ Jordan. “If digestion is sluggish or the microbiome is out of balance, it can impact serotonin production, affecting mood, sleep and even anxiety levels. Additionally, slow transit can lead to systemic inflammation (affecting the whole body), which is often linked to brain fog and fatigue.”

Intrigued? So, how can we find out more about our individual gut transit health? The good news is that testing it is surprisingly simple. 

“One of the most straightforward ways to measure your gut transit time is by consuming foods that are easily identifiable due to their distinctive colour or incomplete digestion, such as beetroot or sweetcorn, and observing when the colour or corn chunks appears in your stool,” says Dr Berry. “This simple method provides an insightful, easy way to track the speed at which food moves through your digestive system.”

Stuart advises jotting down when you eat the foods you’re tracking, then noting down when you see them in your stools. The difference between these two times is your gut transit time. Not a fan of beetroot or sweetcorn? Try a handful of whole seeds, such as sesame, but be aware that these might be more difficult to spot.

If you’ve tested your transit time and didn’t get a result you were hoping for, don’t worry – there are plenty of ways we can all optimise our digestive journeys. 

1. Eat more fibre

Whole foods, fruits, vegetables and whole grains help move things along, so focus on a healthy, diverse diet. 

2. Stay hydrated

Good hydration is crucial for so many bodily functions, and digestion is one of them. “Drinking plenty of water keeps your stools soft and easier to pass,” says Patel. 

3. Exercise regularly

We know that motion is lotion for our joints, and keeping active is just as beneficial for our gut health and digestion, too, as movement stimulates digestion and reduces our risk of constipation and hard stools. 

4. Support your gut microbiome

Include probiotic-rich foods like kefir, yoghurt and fermented vegetables.

5. Manage stress

Easier said than done, but stress is known to slow digestion due to the gut-brain connection. So, take some time to think about what’s affecting your stress levels and what you may be able to tweak so you’re a little calmer. 

And remember: “Everything about your poo is a signal from your gut,” says Stuart. “So colour, consistency, time it takes to go and smell are all messages to pay attention to. Get to know your ‘normal’ so that you can pay attention if something changes.”

Images: Getty