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Why a healthy gut could be the key to weight loss

21 Oct 2022 • 2 min read


Good news: looking after your gut health could help you manage your weight. The latest research suggests your digestive health is not only the key to your overall health but may help with weight loss, too.

Did you know that the microbes that live inside you outnumber your own body cells by 10:1?

Deep down in your large intestine, there are around 100 trillion microbes – mostly bacteria – and collectively, they’re known as your microbiota.

What does gut bacteria do for you?

There are hundreds – if not thousands – of strains of gut bacteria. Some are helpful, some aren’t – and we’re only just starting to discover their roles in looking after our health.

Your gut bacteria help you to: 

  • Digest food
  • Protect against pathogens, such as viruses
  • Provide essential nutrients, enzymes and hormones
  • Manage your metabolism
  • Train your immune system

But they can only do all of this if your microbiome is in balance.

If it’s not, then digestive issues, lethargy, low mood, poor immunity, and weight gain can occur.

The gut-weight link

One of the key areas of gut research focuses on weight loss.

Studies in obese and lean sets of twins have shown that lean twins have a vibrant and diverse microbe community, while obese twins have far fewer useful microbes.1

Gut microbes may alter the way we store fat,2 how we balance our blood glucose levels3 and how we respond to hormones that signal hunger and satiety.4

There’s plenty you can do to improve your gut health and support weight loss – and it all starts with giving your gut a little love.

Ultimate guide for a happy & healthy gut

Gut health is key to overall health. This makes perfect sense, as the gut (also known as our gastrointestinal tract) is the organ system in charge of digesting the food we eat.

Read more

Ultimate guide for a happy & healthy gut

Gut health is key to overall health. This makes perfect sense as the gut, aka our gastrointestinal tract, is the organ system in charge of digesting the food we eat.

Support your gut bacteria

The main goal of any gut-healthy diet is to increase the number and variety of good bacteria in our digestive system.

Here are some ways you can support your gut bacteria:

  1. Minimise stress

Research shows being under stress reduces the number and diversity of gut microbes.

Try and carve out time for activities you enjoy, whether that’s yoga, painting or reading a good novel.

  1. Get active

Studies have found athletes have a greater variety of gut bacteria than inactive people. (5)

Exercise may increase levels of different bacterial strains, while also helping with stress and weight loss.

The role of diet in gut health

Diet is key when you’re thinking about improving your gut health and trying to lose weight.

Here are some ways you can make your diet more gut-friendly:

  1. Limit sugar and processed foods

Excess sugar suppresses beneficial bacteria and allows unhealthy microbes to take hold.

Processed foods are often high in sugar, salt, fats, additives, and preservatives. They offer few nutrients for your gut bacteria to thrive on, so are best avoided.

Plus, processed foods are generally higher in calories than whole foods, so they aren’t a good choice when you’re trying to lose weight.

  1. Fill up on gut-friendly foods

A diet rich in food with non-digestible ingredients (also known as prebiotics) may increase the number of bacteria in your gut.

These foods contain a form of fibre that passes through your digestive system and provides a feast for waiting microbes.

You can find them in fibrous foods like bananas, asparagus, chicory, onions, garlic and leeks, as well as many other fruits, vegetables, pulses, nuts and seeds. Prebiotic fibre such as fruit and vegetables are also low in calories, so these foods are useful for weight management.

  1. Up your natural bacteria intake

Try to eat more foods that contain live bacteria and yeasts, such as probiotics. Some foods are naturally fermented, while others have their live cultures added.

Avoid milks and drinks that are flavoured and sweetened, as this process can remove their beneficial effects. Instead, pick naturally fermented foods.

Here are some of the best foods that can contain live beneficial bacteria:

  • Live, natural yoghurt
  • Kefir – a fermented milk drink
  • Kombucha – a fermented tea drink
  • Kimchi – Korean pickled vegetables
  • Sauerkraut – German pickled cabbage
  • Other pickles
  • Miso
  • Aged, unpasteurised cheese

18 of the best foods for gut health

With the help of Holland & Barrett nutritionist, Isabel Tarrant, we delve into the science of digestion and reveal some of the best foods for gut health.

How do probiotics help with weight loss?

Research has linked probiotics with weight loss. For example, some studies suggest that probiotics could reduce the body weight and fat mass in individuals, as well as improve fat and sugar metabolism too.6

These beneficial bacteria travel through your digestive tract to the large intestine, where they boost the numbers and strains of the microbes that live there.

Eat an abundant, diverse diet

If you’ve struggled with restrictive or calorie-controlled diets in the past, here’s some good news: when it comes to improving your gut health and losing weight, you need to eat more, not less!

Diversity can be a problem in modern, Western diets, but increasing the variety of natural foods you eat is the fastest way to improve your microbiome.

In fact, research shows that dieters who ate a greater variety of healthy foods were more likely to lose weight and fat long term, and were less likely to develop diabetes, high blood pressure and obesity.7

So, try to eat a rainbow of fruit and vegetables, nuts and seeds every day. Try and buy new foods each time you shop, eat seasonally, cook new recipes and experiment with foreign cuisines.

Get out of your food comfort zone, and your gut – and waistline – will thank you for it!

The advice in this article is for information only and should not replace medical care. Please check with your GP or healthcare professional before trying any supplements, treatments or remedies. Food supplements must not be used as a substitute for a varied and balanced diet and a healthy lifestyle.

Last updated: 21 October 2022



Author: Ro HuntrissRegistered Dietitian

MRes Clinical Research - University of Manchester, 2016

Ro Huntriss is a UK-based Registered Dietitian. Ro has over 10 years of experience working as a dietitian and has worked across many different sectors including NHS, private practice, research, digital health, health technologies and supporting commercial businesses.

Ro is a specialist in a variety of areas to include weight management, diabetes, women’s health, gastrointestinal and cardiovascular health. Ro expanded her expertise to a number of areas as she believes that health is not one dimensional and health should be considered from several angles. 

In her spare time, Ro enjoys yoga and netball, playing the piano and is an avid Tottenham Hotspur fan! 



Professional Accomplishments

  • Community Nutrition Professional of the Year 2021 - CN Magazines 

Affiliations/Memberships/Governing bodies


  • Kumar, K.D., Huntriss, R., Green, E., Bora, S. and Pettitt, C. (2022). Development of a nutrition screening tool to identify need for dietetic intervention in female infertility. Journal of Human Nutrition and Dietetics, doi: 10.1111/jhn.13055.
  • Huntriss, R., Haines, M., Jones, L. and Mulligan, D. (2021). A service evaluation exploring the effectiveness of a locally commissioned tier 3 weight management programme offering face-to-face, telephone and digital dietetic support. Clinical Obesity, e12444. 
  • Huntriss, R., Boocock, R. and McArdle, P. (2019). Dietary carbohydrate restriction as a management strategy for adults with type 2 diabetes: Exploring the opinions of dietitians. Journal of Diabetes Nursing, 23: JDN104. 
  • Huntriss, R., Campbell, M., and Bedwell, C. (2018). The interpretation and effect of a low-carbohydrate diet in the management of type 2 diabetes: a systematic review and meta-analysis of randomised controlled trials. European journal of clinical nutrition, 72(3), pp. 311–325.
  • Huntriss, R. and White, H. (2016). Evaluation of a 12-week weight management group for people with type 2 diabetes and pre-diabetes in a multi-ethnic population. Journal of Diabetes Nursing, 20, pp. 65-71. 
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