Could Your Gut Bacteria Be Inhibiting Your Ability To Lose Weight?

Updated: Jul 9, 2019

Almost everyone has made a New Year's resolution to lose weight. And most have failed. But contrary to popular belief, it is not always due to a lack of willpower. Research is now showing that the real reason might be hidden in your gut health.


Weight loss resistance is a term used to describe the situation where people who, despite an appropriate diet and exercise program, are unable to drop excess body fat. Any personal trainer will know this is their worst nightmare! It is often assumed that these people are lying about what they eat or how much they exercise. However science is now suggesting that there are other variables that need to be considered, including our gut bacteria.


The human microbiome is basically the trillions of microbes that inhabit the human body. They are estimated to outnumber our human cells by as much as 10 to one and the latest scientific research suggests they have a huge impact on our health. The bacteria in our gut have an important role to play, From processing nutrients in the foods we eat and synthesising vitamins, to supporting the immune system and regulating hormones.

But if this ecosystem gets imbalanced, the consequences can extend far beyond the intestinal tract. Everything from allergies, diabetes, autoimmune conditions and mental health and obesity have been associated with changes in the gut microbiome.


New research indicates that our gut bacteria affect the way we store fat, how we balance blood glucose levels, and the hormones that make us feel hungry or full. The wrong mix of gut bacteria can even set the stage for obesity from the moment you are born.


Studies began right back in 2006, when scientists first discovered that an imbalance in the microbiome could lead to obesity in animals. Researchers from Washington University found that obese mice had higher amounts of a gut microbe called firmicutes. Which, it turns out, are too efficient at extracting energy from food, breaking down food and increasing the absorption of fat. This was the first insight into the possible connection between gut bacteria and weight loss.

Then in 2013, a study used faecal transplants from humans to mice. They found that healthy mice could be made obese by transferring faecal matter, and the microbes that go with it, from obese humans to the mice. They also found that transferring faecal matter from lean humans to the mice prevented the mice from putting on weight.

The microbiome you have determines how you absorb and process nutrition according to a study in 2016. Researchers found that a gut shaped by an unhealthy daily diet won’t respond as quickly to a healthy diet as a gut shaped by vegetables and fruits that has more varied microbes to begin with. This makes it tricky for anyone starting a health kick after years of an unhealthy diet. You may have to be more patient with results as your microbiome adapts and changes with your new lifestyle.

Another 2016 study suggested that yo-yo type weight gain could be the result of specific strains of gut microbes. The researchers found an intestinal microbiome signature that persists after successful dieting of obese mice, which contributes to faster weight regain upon re-exposure to a less healthy lifestyle. The changes to the gut microbiome brought about by obesity were observed to last five times longer than the actual time spent dieting. Not good news for those trying a short-term diet after years of being overweight.


Now that we know there’s more to the weight loss story beyond a healthy diet and good exercise program for many people, what should we do? Well, if there’s one thing we know, it’s that everyone’s microbiome is as unique as their fingerprint – no two people are the same.

It really depends on your health history and lifestyle from birth, as well as what exactly is going on inside your gut. The approach you take will depend on whether you have:

Not enough good bacteria, too many of specific types of bacteria, particularly nasty types of bacteria, parasites or yeast/fungus.

But, as with a lot of things, there are a few basic gut health tips you can use to get started in the right direction.

These include:


Eat real food, mostly plants and as diverse as possible. Eat the rainbow, as they say. Fibre-rich fruits and vegetables are what help stimulate the growth of good bacterial species. The average person is estimated to only eat around 20 different foods per week, which is way too low considering our ancestors are thought to have had as many as 150. So get out of your standard routine and look to mix things up by adding a few new ingredients each week.


Reducing inflammatory foods is critical to healing your gut microbiome. These include foods you are sensitive or intolerant to as well as some processed foods, alcohol and sugar. If you have not had a food sensitivity test or done an elimination diet, you can start with eliminating some of the most common culprits; gluten, wheat, dairy, eggs, and  soy. After two to four weeks, bring them back in one at a time and see how you feel.


Foods like yogurt, sauerkraut, kefir, kombucha, miso, microalgae such as spirulina and chlorella, and kimchi are a few of my favourites. You can also supplement with a good quality, practitioner recommended probiotic, like this one.


There’s a limit to what basic gut healing dietary strategies can achieve if you have an undiagnosed gut dysfunction. If you’re struggling with weight loss resistance and also experience any digestive discomfort, then finding and healing your root cause is key to any lasting improvement.

So, if you’re embarking on a new year’s resolution to lose weight but are worried that gut dysfunction could derail your plans, get in touch and let’s sort you out. Healing the gut is a journey.

If you're ready to start your health journey today and want all the tools, support and knowledge to ensure your success, book a free 20 minute discovery call with me today.

Chrystie x

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© 2021 The Gut Health Nutritionist

DISCLAIMER. As each person is different, individual results cannot be guaranteed.

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