Fasting: How Skipping Meals Can Burn Fat & Increase Lifespan

If I told you there was a way to burn body fat, lower blood pressure, decrease inflammation, boost cell repair and increase longevity you would probably think that I was about to promote a revolutionary new drug or supplement right?

Well this is not the case, in fact you can reap all these benefits by utilising something that doesn’t cost a cent (in fact it will save you money) and can be implemented by most people right this very moment – no fancy gadgets to order, no diet books to read, no supplement stacks, nothing.

Fasting: How Skipping Meals Can Burn Fat & Increase Lifespan

The title gives it away! To increase fatty acid oxidation, cell repair, lower inflammation and increase longevity all you need to do is skip a few meals, also known as ‘fasting’. It really is that simple.


What actually is ‘fasting’?

There was a time not long ago where we didn’t always have a ready source of food always at hand. Pre agriculture, humans were hunter gathers, meaning our bodies were equipped to go extended periods without food. This extended period of without food is known as fasting.

I need to be clear - it’s not starving yourself – defines starving as “to die or perish from lack of food or nourishment, or to suffer from extreme poverty and need”.

Fasting, on the other hand, is defined as “abstain from all food, or to eat only sparingly or of certain kinds of food”.

The big differing factor is choice – if you decide to go without food for whatever reason (health, religious, medical etc) its by your own free will and you could easily open the fridge and break a fast.

If you are thinking that the idea of fasting would involve ‘suffering from extreme poverty and need’, especially if you are used to eating every 2-3 hours – I need to tell you two things:

  1. It’s really not that bad, trust me. And,
  2. Remember - we live in a well of comfort. Chances are if you’re reading this on a shiny tech gadget you live in a world of abundance, freedom and choice. You could walk to your local McDonalds at any hour and buy some food for a few dollars. You are not going to die from going without food for a few hours and you’re probably not close to suffering from extreme poverty or need.

But I digress. Fasting (also referred to as ‘intermittent fasting’) in modern society is therefore the simple act of deciding that you are going to skip a meal or 5…

Now why would anyone consider to devoid themselves from the pleasure of eating? Good question, but I have some good reasons. Read on!

Why should I fast? 

Fasting for Health & Wellness

Fasting is a great way to improve mitochondrial efficiency (the cells power plants) and optimize the fat burning processes.

As mentioned earlier, we are biologically wired for this. Fasting, or Intermittent fasting (IF) increases a cellular process called autophagy. Autophagy is the bodies way to clear our waste. Think about building a skyscraper – if the building managers focus is purely on ‘build’, you will end up with a lot of waste materials lying around the building site – empty cement bags, broken tools, off cuts etc. If no time is allocated to cleaning up and waste removal the job site will become dangerous (workers tripping over waste etc.), the work will become less efficient (having to work around waste), and the end product may be flawed.

The same applies to a cell – if we consistently tell the cell to build and grow (through frequent meals, too much training, chronic stress states, lack of sleep & recovery etc), our cells don’t have time to clear out toxic waste… the end product (our body and health) takes a hit as a result.

So what’s so good about autophagy? Well studies have shown that it has:


  • Tumor suppressive properties
  • Inhibits cancer development
  • Supports immune function
  • Boosts anti-tumor antigens


Also, extended fasts have been showing to boost immune function, at least in mice. A study published in the science journal Cell and found that multiple cycles of extended fasts (48hours) protected mice against the harmful effects of chemotherapy treatment and led to a regeneration of bone marrow stem cells along with higher white blood cell counts.


The authors of the study - which can be read here - concluded

“... that cycles of an extreme dietary intervention represent a powerful mean[s] to modulate key regulators of cellular protection and tissue regeneration, but also provide a potential therapy to reverse or alleviate the immunosuppression caused by chemotherapy treatment and ageing”



If you want to live longer, eat less – so the studies show. Calorie restriction (or CR) has been shown to increase longevity in a wide ranges of species, while also improving various dietary markers.

If the thought of living in a semi starvation state doesn’t sound very appealing (note – some people actually do this!) then you will be happy to know that fasting has also been shown to increase longevity, without requiring any cut in calorie consumption.


Fasting for Fat Loss

From a fat loss point of view, fasting has been shown to improve insulin sensitivity, improve glucose uptake, and lower body fat. Also, while you are fasting your body is running off fat, strengthening the body’s ability to use fat as its primary fuel, diminishing the need for carbs – leading to a cleaner burning cell (blog post on this coming soon!)

Along with autophagy, the benefits to fasting are quite extensive. The guys at Precision Nutrition have put together this extensive list:

Benefits of Fasting:

  • blood lipids (including decreased triglycerides and LDL cholesterol)
  • blood pressure (perhaps through changes in sympathetic/parasympathetic activity)
  • markers of inflammation (including CRP, IL-6, TNF, BDNF, and more)
  • oxidative stress (using markers of protein, lipid, and DNA damage)
  • risk of cancer (through a host of proposed mechanisms; we’ll save them for another review)


  • cellular turnover and repair (called autophagocytosis)
  • fat burning (increase in fatty acid oxidation later in the fast)
  • growth hormone release later in the fast (hormonally mediated)
  • metabolic rate later in the fast (stimulated by epinephrine and norepinephrine release)


  • appetite control (perhaps through changes in PPY and ghrelin)
  • blood sugar control (by lowering blood glucose and increasing insulin sensitivity)
  • cardiovascular function (by offering protection against ischemic injury to the heart)
  • effectiveness of chemotherapy (by allowing for higher doses more frequently)
  • neurogenesis and neuronal plasticity (by offering protection against neurotoxins)

Amazing huh?

Now if you’re thinking ‘why haven’t I been doing this for ages’, well you probably have. Unless you’re getting up for a midnight snack every night you’re most likely fasting 8-12 hours every time you go to sleep!

But if you want to truly optimize your health and fat loss you may want to look at increasing not only the fast duration, but the frequency of fasts.


Who Should Fast?

Fasting isn’t recommended for everyone. If you have any of the following issues I wouldn’t recommend fasting just yet:

  • Diabetes
  • Adrenal or Leptin Hormonal Issues (if you think you have these issues be sure to check out my ultimate health protocol).
  • You are pregnant
  • You have serious thyroid or gut issues
  • Finally, females in particular may need to be careful when fasting – you must make sure you are in a pretty healthy state before doing this.

 If you put on our ancestral hats for a moment, fasting was for the healthy, fit and active hunters and gathers. Those with health issues (the sick) would stay back at camp – close to a food source.

Also, if you’re currently eating a standard western diet (lots of refined carbs, lower fat etc) you may want to change over to a higher fat, lower carb diet before starting on a fasting protocol (though IF will help the body from being a sugar burner to a fat burner, it will make fasting very difficult on the body - and mind. All of a sudden your body would be forced to use fat and proteins as fuel - instead of the regular carb hits it was used to)

The body stores mainly fat as fuel, amino acids can be released from protein, and some (but very little) glucose is stored in the liver and muscle. 

Extended periods without food, albeit beneficial for us, require a body (and mind) that is capable of going without food for such long periods. The body adapts to our diet. Different cellular machinery, enzymes and vitamins are involved in metabolizing glucose, fatty acids and amino acids. 

If the diet you eat provides these elements at similar proportions as to what is 'released' or cannibalized while fasting (i.e., breaking the body down for fuel) then you will be well prepared for a fast. Fasting will be easy.

It’s for these reasons that when I work my my fat loss coaching clients I spend the first 1-2 months transitioning them to a higher fat diet. During this time I remove all snacking – so they are doing mini fasts between meals (5- 6hours) and overnight fasts (10-12 hours). After a few months I will then introduce day fasts (skipping lunch – so a 12 hour day fast and a 12 hour overnight fast), then when they are ready introducing a weekly 16 hour fast and eventually a 24 hour fast.

Again, if you’re not eating a high fat, lower carb diet I highly recommend changing your diet over 2-3 weeks before introducing fasting. For resources on how to do this please see the protocols outline in my Fat Loss ebook or be sure to download my free fat loss diet report by clicking HERE


How Do I Fast?

So how do you go about enjoying the benefits of Fasting? There are two main methods:


  1. Increasing the frequency of fasts – I.e. Fasting 12 hours over night, then 12 hours during the day (skipping lunch)
  2. Increasing the duration of a fast – I.e. Fasting overnight then skipping breakfast and maybe lunch going for a 14-24+ hour fast


With my clients I generally use the following two fasting protocols:

  • 12 hour day Fasts. 

This is pretty self-explanatory. You are to go 12 hours without food during the day.  If you eat at 630am, skip lunch, and eat dinner at 630pm you have completed a 12 hour fast (and reap the benefits of extended fasts). The great thing about eating this way is that you actually achieve two 12 hour fasts in one 24 hour cycle. If your dinner is at 630pm, then you don’t eat again until 630am the next day you have performed a 12 hour fast overnight. Well done. 

  • 24 Hour Fast.

Yes you read this right. 24 hours without food. It’s not that hard I promise. All you do is have one BIG breakfast within an hour of rising, skip lunch, skip dinner and go to bed.
If you find come dinner time you feel terrible and MUST eat, then that’s ok. Eat dinner and be content that you performed a 12 hour day fast and you’ll soon do a 12 hour overnight fast.

Finally, I need to point out that I'm no doctor, just some guy who reads a lot of books and is into health! So please do your own research before making any dietary changes and be sure to get your doc's approval!

Questions & Concerns?

Are beverages allowed?

It really depends on what your goal is. Your beverage consumption should be restricted to tea, coffee (black) and quality spring water for optimal results. I recommend avoiding any artificial (or natural) sweeteners while on a fast.

Training Whilst Fasting
I don’t recommend doing an interval session or a high intensity weights session during a your first few attempts at fasting – especially for longer fasts. Save your training sessions for day when you can eat after training.

However, once you have become comfortable with regular 12-16+ hour fasts then you could look at training during a fast. There are a number of health, performance and fat loss benefits from training in a fasted state. I personally prefer fasted training and during a recent 3 day fast I did a HIIT session on day two without any ill consequences.

NB – by ‘training’ I mean intense exercise like sprints or weights. Walking, yoga etc are fine to do in a fasted state.


Can I take supplements during a fast?

You can do whatever you want! A true water fast would be devoid of supplements. If you are concerned about muscle lost during an extended fast you may want to supplement with a teaspoon of Essential Amino Acids every 14 hours or so.  


What about fasting for woman?

That’s a great question and requires a detailed response. Thankfully there is a detailed response posted on the website 


Other questions? Please post them below.

 If you are tempted to give fasting a go (remember to check with your doctor first!) please keep me updated on how you go! Though if you're used to eating a higher carb diet with meals every 2-3 hours you may want to make some dietary changes before jumping into the world of fasting headfirst! My free Fat Loss Meal plan will help here (even if your goal isn't fat loss this protocol will help the body become a more efficient fat burner). You can download that here.

Also, make sure you sign up to my newsletter as I have recently done a 3 day fast and will be sharing my experiences with my email subscribers!


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This blog post was written by Alex Fergus. Alex is an ISSN Sports Nutrition Specialist, Fitness Professional and certified Superhuman Coach who continues to expand his knowledge base and help people across the world with their health and wellness. Alex is recognized as the National Record Holder in Powerlifting and Indoor Rowing and has earned the title of the Australian National Natural Bodybuilding Champion. Having worked as a health coach and personal trainer for over a decade, Alex now researches all things health and wellness and shares his findings on this blog. Learn more about Alex's Credentials HERE.

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