Does smoking affect the keto diet?

I was catching up with a friend of mine, and he commented on how much weight I’ve lost on Keto and he is thinking of doing it himself.   He was asking me a bunch of question, but one stumped me.  Being a smoker himself he asked if ‘Smoking affects the keto diet’ and unfortunately couldn’t answer him because I didn’t know, so I did some research and this is what I discovered.

According to the National Institute of Health, smoking increases insulin resistance.  Insulin resistance means your body doesn’t react to insulin correctly and has to produce more to compensate, however when insulin is present in the blood, fat metabolism is greatly reduced.  So I would say smoking does affect the keto diet in a negative way since it contributes to blocking your body’s natural fat burning mechanism. 

So what is insulin?

When you consume carbohydrates, like from a meal or drink your digestive system breaks down the carbs and releases the sugar (Glucose) into your blood stream.  Your body likes to keep the sugar level in your blood at a certain level, and if the sugar level should spike up too high your Pancreas will jump into action and produce insulin to remove the excess sugar from your blood.   Insulin moves some of this sugar directly into cells for energy and into a bunch of other areas like muscles and the liver.   The insulin literally unlocks the cell allowing the sugar to be stored in it.  All the excess sugar then gets stored as fat around the body.  The body stores the sugar and fat away for later consumption by your body.

For a more detailed explanation of what insulin is, check out this youtube video,

Why is insulin resistance bad?

Insulin resistance is when your cells no longer function the same in response to the hormone insulin.  The cells struggle to absorb the sugar into them because the cells are becoming resistant to the key (insulin) that unlocks them for energy storage.  This causes the blood sugar level to rise, which causes the pancreas to pump out even more insulin and the result is the excess sugar is stored as fat.  This is bad because insulin resistance is generally a precursor to Type 2 diabetes and a host of other symptoms like:

  • Lethargy
  • Unable to focus (brain fog)
  • Weight gain
  • Increased hunger
  • Increased cholesterol
  • Increased blood pressure

Over time people with insulin resistance that are unaware they have it may develop type 2 diabetes or other chronic conditions.  So the bottom line is being insulin resistant is a big health issue that should be taken seriously.  I’ve read that insulin resistance is as high as 24% in US adults aged 20 years and over, that’s 1 in 4 people, I was absolutely shocked to read that.  If you have any of the following conditions you might be at risk of being insulin resistant:

  • A history of diabetes in the family
  • If you are overweight or obese
  • If you have excess stomach fat
  • If you smoke regularly
  • If you don’t exercise much

More info can be found here (NIH Gov site), along with all the symptoms.  You should ask your doctor to perform a test if you have any real concerns.

How does insulin resistance slows fat loss

So we now know insulin is responsible for storing fat, right?  Well, it has a counterpart called Lipase, which is an enzyme responsible for releasing fat.  The problem is Lipase doesn’t function really well when insulin is present in your blood, and if you’re insulin resistant you produce more insulin than you normally would, thus reducing how to affect your bodies fat burning mechanism.  This is a big problem if you follow a Keto lifestyle as your body relies on Lipase to release that fat from storage for energy.

How does smoking affect insulin resistance?

‘Smoking (also in habitual smokers) acutely impairs insulin action and leads to insulin resistance’.  This is an excerpt of a publication by the US National library of medicine website.  (Source:  I’m not going to go into the medical detail as to why smoking causes insulin resistance because it’s technical and I barely understand it myself.  However, the link is there above for you to have a read.  The fact of the matter is that it does and if you are on the keto diet you want your body processing insulin correctly.  I also read a bunch of info across many diabetic websites both Government run and private website, and they all recommend quitting smoking as it interrupts the effectiveness of insulin in your body.

How Insulin resistant can affect building muscle mass

So for myself, I have started to go to the gym to help improve my weight loss results.  While researching how smoking effects keto I learnt that insulin is important for gaining lean muscle mass. Who knew insulin is so vital to so many systems of the body.  I love the human body, it is so fascinating, anyway I digress.

Insulin acts as a key that unlocks the cells in our bodies, apart from storing glucose in the cells, it also allows all those fantastic amino acids in that later get converted into skeletal muscle proteins.  However, when we are insulin resistant, we are locking the cells and creating resistance from the cells receiving amino acids which prevent the growth of muscle tissue.

Insulin lean muscle mass

Amino acids are important to your body especially after training as it assists with various processes like feeding your muscles, like repairing and growing your muscles.  So becoming insulin sensitive (non-resistant), we allow our cells to perform normally and to build muscle at a better rate.

Does smoking Marijuana affect Keto?

Well, the answer to this one surprised me.  Being a casual pot smoker myself I was naturally curious, so back to the National Institute of Health, I went looking for the answer.  Bare in mind the study 40+ years old and I imagine more research needs to be done, but the result seems somewhat positive.

“Of the participants in our study sample, 579 were current marijuana users and 1975 were past users. In multivariable-adjusted models, current marijuana use was associated with 16% lower fasting insulin levels and 17% lower HOMA-IR (insulin resistance). We found significant associations between marijuana use and smaller waist circumferences.”

Now I’m not advocating everyone go blaze up, but for those of you that do it looks like it might be keto friendly from an insulin resistant point of view.

The only disadvantage I could come across is the munchies, and I think the best way to combat that abstains from eating or pre-prepare some keto meals beforehand so you are not raiding the cupboards.  Keto fat bombs are a great idea.  OMG Brilliant idea, ‘Keto Hash Bombs’.  I am going to have to try that one and get back to you.

Quitting smoking tips

We all know smoking is bad for your health, but I am not a smoker. However, I did grow up with a Stepdad and sister that both smoked.  That is they both ‘did’ smoke, as in past tense. My stepdad died of cancer and my sister finally give it up after 25 years.  I remember both of them coughing and sputtering saying they should quit, in particular my stepdad would curse after a coughing fit saying ‘These f***ing things’.  I saw it first hand how hard it is and know that my heart goes out to you.  I don’t know you, I may never know you, but I believe in you and in the power of one.  You are the ‘One’, you have it within to quit.

“The power of one is above all things the power to believe in yourself, ofen well beyond any latent ability you may have previously demonstrated. The mind is the athlete, the body is simply the means it uses to run faster or longer, jump higher, shoot straighter, kick better, swim harder, hit further, or box better.”

― Bryce Courtenay, The Power of One

Here is some website with a bunch of resources on them to help you with quitting smoking.  If that’s something you want I wish you well in your journey.


New Zealand

USA (Tailored specifically towards women)




You are here because you are on Keto and you are a smoker.  I can assume you are doing the ketogenic lifestyle to improve your health in some way, whether it be too loose weight or one of the other health benefits.  Apart from the negative impact of smoking on your health, more than likely it is also impeding your keto results as well.

If you liked my post, please subscribe and share on social media and as always, I wish you well on your Keto/LCHF journey.