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Why can some people eat whatever they want...and not put on weight?

Have you ever wondered how some people seem to be able to eat desserts after their meals, cakes every now and again, pizza whenever they want to.... and yet never seem to put on any weight?

Have you always thought it was just that you “have a slow metabolism” or because you “just have “bad” genes” that you struggle with your weight? ...

Have you always thought it was unfair that you only have to LOOK at something unhealthy and you seem to put on weight?...

Well there is one reason that some people may be able to get away with eating more calories, a wider range of foods, having a dessert every now and again ...without it having any negative effects on their bodies - and it relates to what is going on in their gut...

You might have heard of something called your MICROBIOME in a yoghurt advert. Well it is basically the range of micro-organisms that are in your gut (and there are in fact more micro-organisms in your gut than cells in your body). Many of these micro-organisms in our gut are beneficial to us - they help us to extract nutrients from our food and do many other things that are beneficial to our well-being. However there are other micro-organisms in our gut that can be harmful and that have been connected to a range of conditions including obesity (and even things like depression and anxiety, as we will see later).

So research suggests that the state of your micro-biome (how diverse it is and how many more good micro-organisms than bad ones you have) can have a huge impact on many aspects on your health - including on how you metabolise food. For example, studies have shown that transplanting the micro-biome of a lean mouse into an obese mouse, allows that obese mouse to return to a healthy weight. Studies also show that humans with a lot of a certain type of harmful bacteria in their gut are much more likely to be obese. Certain of these harmful bacteria have also been shown to increase the number of calories an individual extracts from food - so literally some people DO just take in more energy from every food they are consuming.... because they have more of these “bad” micro-organisms in their gut.

So it’s not your fault, if you are desperately trying to track calories on some app - miserable, wondering why your slim friend can chow down on whatever she wants, without having to worry ...

It could just be because of the different states of both of your micro-biomes!

It can affect your mental health too

New research also shows that the state of our microbiome can also have an impact on the state of our mental health. For example, a study conducted by Clapp et al. (2017) on the link between the state of the microbiota and mental health highlighted "the importance of a healthy microbiome, particularly the gut microbiota, for patients suffering from anxiety and depression, as dysbiosis and inflammation in the CNS have been linked as potential causes of mental illness, there is a large body of literature that supports a role for microbiota-brain communication in mood and emotional domains, and they demonstrate that dietary interventions may have potential in mental health”.

So not only does the state of your micro-biome affect how you metabolise food and how much energy you take from food - but it can also affect your mood... and if you are feeling anxious or low, what might you turn to in order to feel better?... you guessed it - more food!

So can you do anything to change the state of your micro-biome?

Our base-level micro biome is actually formed in the first few years of our life. So things such how our mother delivered us (C-sections can unfortunately negatively affect the state of our micro-biome), whether we were breast-fed and what we were exposed to as a young child - all affect the state of our micro-biome.

HOWEVER - our diet and the way we live our lives day-to-day also has a great impact on the state of our micro-biome. So we can all do things to improve the state of our micro-biome - helping those good micro-organisms to thrive (and to ensure the outnumber the “bad” guys that can negatively affect the state of our health and our waist-lines). As described by Foster (2017), one of the things that has an important impact on the state of our microbiome is our diet and lifestyle. As Clapp et al. confirm "Diet alterations can have significant impact on the gut bacterial composition in as little as 24 hours" (2017). So by eating well (at least most of the time - so around 70% of the time), getting enough sleep and managing our stress levels effectively - we can all improve the state of our micro-biome.

So what do I mean by eating well?

Unfortunately the “bad” bacteria love foods like sugar, fruit juice, refined carbs, pastry, ultra-processed foods full of trans fats ... you know - the standard stuff that you would consider to be unhealthy. So eating all of these foods very regularly can allow the “bad” guys in your gut to out-number the “good” guys.

The “good” bacteria however love things like vegetables and fibre-rich foods. If you want to boost the state of your micro-biome you should also include some pro-biotic and pre-biotic foods into your diet daily.

Pro-biotic foods are foods which introduce more “good” micro-organisms into your gut and include things like:

- Kefir


-Yoghurt (though I mean things like Greek yoghurt which are not full of sugar)

- Other fermented foods


Pre-biotic foods are food which feed the “good” micro-organisms that you already have in your gut and include things like:

- Asparagus

- Onion

- Garlic

- Tomatoes

- Carrots

- Chicory Root

If you include some of these foods into your diet every day - your micro-biome will be so healthy - that you can actually get away with eating the less healthy foods some of the time. This is why I encourage my clients to focus on eating healthily the majority of the time (around 70% of the time)- but to allow themselves the occasional treat every now and again. If your micro-biome is in good shape - it can handle it! All of this also shows that the model of just counting calories really over-simplies the process of losing weight .... because if your micro-biome is not in good shape, you are just metabolising all of your food differently.

So take care of those little guys in your gut ... and trust me - they will take care of you too!

“We inherit every one of our genes, but we leave the womb without a single microbe. As we pass through our mother's birth canal, we begin to attract entire colonies of bacteria. By the time a child can crawl, he has been blanketed by an enormous, unseen cloud of microorganisms--a hundred trillion or more. They are bacteria, mostly, but also viruses and fungi (including a variety of yeasts), and they come at us from all directions: other people, food, furniture, clothing, cars, buildings, trees, pets, even the air we breathe. They congregate in our digestive systems and our mouths, fill the space between our teeth, cover our skin, and line our throats. We are inhabited by as many as ten thousand bacterial species; those cells outnumber those which we consider our own by ten to one, and weigh, all told, about three pounds--the same as our brain. Together, they are referred to as our microbiome--and they play such a crucial role in our lives that scientists like [Martin J.] Blaser have begun to reconsider what it means to be human.” ― Michael Specter

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