Firth Fitness
Queen's University Belfast Physical Education Centre Botanic Park, Belfast BT9 5EX

Intermittent Fasting for Fat Loss

I came across the concept of intermittent through a blog leangains. With 20 years experience in the industry i was a little bit sceptical.  After all, i have been previously taught that the “5 – 6 small meals a day” approach was the way forward, especially when looking to reduce your body fat. What if all that we have been told isn’t exactly true?  I mean if I suggested to you to train in a fasted state including resistance and cardio and then wait several hours before feeding, you would think i was mad.  What about the risk of burning off precious muscle tissue you would say?

Well i have found that intermittent fasting has helped me reduce the stubborn bits of body fat that have been difficult to remove up until now.  I have always been lean and blessed with a high metabolism, but still would carry a little body fat on the lower abs and lower back and this would stop me from being as lean as i would like.  The thought of increasing my cardio or reducing my carbs any further really doesn’t appeal to me as this would be a lot of work and only be a very short term fix.  So I have been researching other ways of getting to that next level of “leanness”.

I am sure you all have heard the concept of performing cardio first thing in the morning on an empty stomach, as this leans towards accelerated fat burning more than any other part of the day. Although this is true and you will reduce your overall body fat without question, if you want to take it to a whole new level then a radical approach has to be taken.  You see, once the body reaches 10% in males and 15% percent in females it becomes very “reluctant” to let go of that last little bit of body fat, it’s a survival instinct!

This is where intermittent fasting comes into play.  As with many dietary approaches, there are many opinions about what is “best” and, in this case, the optimal length of time to fast for.  The first type of fasting I heard about was “Eat Stop Eat” by Brad Pilon, who irons out many myths associated with the concept of “metabolic shut down” and “how much protein” we actually need to build and maintain lean muscle mass, while training.  Eat Stop Eat advocates two separate fasts per week, each lasting 24 hours (usually evening to evening).  The advantage of this approach is that you can create a massive calorie deficit over the entire week just from 2 fasts. One of the disadvantages though, is that some people (me included) may tend to over-compensate once the fast is over. In other words you might stuff your face and undo the calorie deficit. So this approach still requires a lot of will-power, especially when you are just starting out.

The second approach to this concept of fasting I have been interested by is The Warrior Diet.  This method involves, not so much complete fasting but to “graze” on low calorie foods throughout the day time (as hunters/warriors used to), such as vegetable, berries and some nuts. Then come evening time, you have one large meal incorporating all the other food groups such as protein, fats and carbs all in one.  This diet is meant to speed your metabolism during the day and increase your focus and alertness because you are not digesting food or concerned about your next meal. Blood sugar levels remain low and you don’t get those pesky hunger pangs or fatigue in the afternoon.  This approach may suit people who find it difficult to plan healthy meals around work or during outings.   

The most appealing and for me the most successful approach is called Lean Gains.   The idea is that you fast for 16 hours (say from 8pm to 12pm the next day) followed by an eight hour re-feed period (12pm to 8pm).  Within the 8 hour re-feed you have the opportunity to eat larger, more satisfying portions, while still restricting your calorie intake.  You can divide the meals up into larger or smaller portions depending on what suits best. The great thing about this method is that, while you are eating less, it doesn’t feel like it.

Now here for the Science Behind it all

Why is IF so much better for fat loss that the traditional 5-6 small meals per day or low carb approach? Well the key to IF is how the hormones within the body react to the fasted state.  To explore this further I will briefly summarise Brad Pilon’s (author of Eat Stop Eat) explanation the role of certain hormones in fat loss:

  1. Insulin – A power hormone that is released whenever we eat. Its role is to signal the storage of the energy from our food in the form of glycogen or fat.  In addition to this, when insulin levels are elevated, your body is unable to release fat from the cells to use as energy.  In other words, when insulin is elevated, you can store fat and you CAN’T burn fat.  Therefore, it goes without saying that while in a fasted state, insulin levels are extremely low, and your body is free to release body fat for energy.  The “opposite” hormone to insulin is glucagon. So insulin is fat storing, while glucagon is fat burning (simply put).
  2.  Adrenaline and Noradrenaline – These are more commonly known as the “fight or flight hormones” and are part of the sympathetic nervous system.  When released they enable your body to utilise energy from stored glucose and fat more efficiently.  Fasting triggers both these hormones.  When the body is in a fed state, it tends towards the para-sympathetic nervous system which controls functions that do not require immediate action, and is slower and has a “sleep inducing” effect when it’s more dominant (like after a meal).  This could explain why I have found I train better in a fasted state.
  3. Human Growth Hormone (HgH) – While many celebrities pay ridiculous money for HgH injections to help with looking younger and staying lean into older age, they miss out one massive bonus of fasting which costs nothing.  Your HgH levels can increase 6 fold while in a fasted state.  Fasting triggers “growth hormone response”, which prevents muscle loss during the fast.  Because of this your metabolism increases, mainly down to the fact that muscle is largely responsible for metabolism. It is only after 36 hours of fasting that the metabolism will start to slow. In addition to this HgH also enables the process of releasing fat stores for energy.  Therefore it is said that HgH, not glucagon, is the dominant hormone during a fast.

 So as you can see it is not just about creating a calorie deficit that makes IF so successful.  Although eating less is very important to losing body fat, it’s not necessarily about eating less more often.  The 5-6 meals per day approach may reduce calories for some but, insulin is higher, the parasympathetic nervous system is more dominant, and hgh is lower.  Therefore, for most of a 24 hour period your body actually favours fat storage, not fat burning.  You may burn off more fat with early morning fasted training, or ward off extra fat gains by reducing calories, but the stubborn fat will still linger. 


Benefits of Intermittent Fasting

 There are many benefits to intermittent fasting, the first that comes to mind is time saved not having to think and prepare endless snacks and meals for the day ahead, but the more interesting thing is the actual health benefits associated with IF.  Below are some of the health benefits that you can expect with IF:

  • Reduced blood glucose and insulin levels (markers of improved health and may help diabetic or pre-diabetics control blood sugar levels and side effect associated with elevated levels)
  • Increased fatty acid oxidation
  • Maintenance of lean mass (muscle)
  • Reduced inflammation
  • Reduced oxidative damage
  • Increased cellular stress resistance ( of the heart and brain)


How to Start IF

Below is an example of how to start your IF,

Mon: last meal or snack 8pm

Tues: Meal one 12pm – 1pm (largest meal of the day)

Tues: Meal two

Tues: Last meal or snack 8pm (repeat)

As you can see from the example above you have one main meal after you come of your fast, this is your biggest meal of the day. Then this is followed by two smaller meals before repeating the process. The key thing in the programme is that when in a fasted state you must try to perform some type of exercise. This doesn’t necessarily have to be high intensity exercise it could be as simple as going for a long brisk walk.  Brad Pilon also highlights the importance of lifting during a fast.  Stimulating the muscles will remind your body you still need them and will reinforce the need for protein synthesis and hgh to build or maintain muscle mass, whatever is needed, or indeed trained for.

To learn more about why IF is so effective for shifting stubborn fat, click the link here

In addition for this approach working for me, my partner, Marianne, is also getting great results. So for all you female or males who are interested in her success, not just with IF, but if you’re interested in FREE workouts head over to her blog myomyTV

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    1. Good post! I agree IF is great and Leangains is the superior option for fitness, fat loss and muscle.

      Btw the url to stubborn fat on Leangains is broken in your html code – here’s the right one:

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