Ladies and gents, here we go – one of my most requested blog posts in recent weeks! Is it just me or is everyone harping on about intermittent fasting? Just another diet fad, you may say, another ‘cure’ to burning fat and getting trim.
I too was sceptical at first.
I mean, ultimately Lean Living Girl is all about promoting an incredibly balanced lifestyle that gets you to your goals WITHOUT any kind of harsh restrictions, ridiculous diets and a seriously unhealthy relationship with food and fitness, because who wants to live like that? But, my lovely readers, I also feel as though it’s my responsibility to help lay out the facts for you, so you can make your own decisions about the best way to get there, and at the end of the day, if science has discovered something ‘new’, (fasting isn’t actually a new phenomenon at all, it’s been round for decades) that could help us not only burn fat more effectively but also increase the general health and well-being of our bodies, then in my opinion it’s worth a post!
So, what is intermittent fasting?
There are a few types of intermittent fasting, but ultimately it is when you eat your calories or consume your meals during a specific, restricted time frame.
What are the different types?
Realistically, you can design your intermittent fasting with whatever suits your body and schedule best, but below are the three most common types of intermittent fasting:
You may see the different states referred to as the ‘fed state’ (eating and digesting) and the ‘fasted state’ (when the last meal has been completely absorbed and the blood sugar returns to baseline).
- The 16 hour fast.
This is when you fast for 16 hours in a 24 hour period, and consume all your normal meals within the balance 8 hour period. The most popular time frame is eating between 12-8pm, and then fasting from 8pm until midday the next day. It makes sense as most people find it easier to skip breakfast rather than dinner but again, this can be adapted to suit you.
- The 24 hour fast.
As you may have guessed, this is when you fast for a full 24 hours! This can be done once a week, every two weeks or even once a month.
- The 5:2 Fast.
This is pretty well known to a lot of people since the release of the 5:2 diet book, but this type of intermittent fasting is when you eat normally for 5 days a week but for 2 days (whichever you choose), you only eat 500 calories in the entire day. Those calories can be in one meal or in 3 meals, at any time of that day.
Personally, I’m not an advocate of this type of intermittent fasting but I will discuss why, and my thoughts on the other two most common type, below.
First, what are the health benefits of intermittent fasting?
And WHY can it help you lose fat?
So the theory goes like so;
When we eat food, the body is in what’s known as the ‘fed state’ i.e. it is digesting and absorbing the food. This process takes between three to five hours* and is characterized by high levels of nutrients in the blood. In this fed state, insulin is often relatively high (or very high depending on what you eat) and given the fact insulin promotes the uptake and storage of fat, it’s extreeeemely difficult to even start thinking about burning fat during this time.
This is what’s known as the ‘post–absorptive state’ i.e. the fasted state; when the body has completed the digesting and absorption of your meal. The body will be looking for sources of energy to keep it functioning and it’s first point of call is going to be your glycogen stores (your carbohydrates). It takes about 8-12 hours for these stores to deplete which is when the body will turn to … you guessed it … fat stores!
This is why research talks about a 16 hour fast, as the first 8-12 hours aren’t even tapping into fat stores. Hence the real benefits are going to be occurring at around 8am till when you eat again at midday.
So that’s the science behind how intermittent fasting can help you lose weight but what about it’s benefits on the whole?
1) Increased blood sugar control and insulin sensitivity.
Insulin is a hormone in our body that is released in response to the food we eat, in varying degrees, most significantly with sugars or simple carbohydrates. If one were to pump their body full of things like doughnuts, white bread, sugary drinks, sweets etc all day long, the cells can become extremely desensitized to the effects of insulin.
And what does insulin do? Well, it causes fat cells to absorb glucose and fatty acids i.e store fat. So decreased sensitivity = permanent high levels of glucose = therefore (most likely with time) Type II diabetes.
Intermittent fasting has been shown to improve blood sugar control by lowering blood glucose and increasing insulin sensitivity.*
2) Increased cell turnover and repair (Autophagy).
Whilst this is constantly happening throughout our bodies day to day, fasting has been shown to boost levels of Autophagy. This is effectively like the body’s ‘cleaning out’ system where it removes toxins, dead cells, damaged cells and generally gets rid of everything not performing to its best level.
As a result, it has been shown to slow down the ageing process, reduce inflammation, generally optimize bodily functions and even lead to decreased risks of cancer.
3) Fat Burning
The reasons why this occurs are explained as above in the different phases of intermittent fasting.
4) Increased growth hormone
Studies such as these (Here, here) have shown fasting to increase levels of growth hormone in the body. Growth hormone supports a healthy body composting by increasing lean muscle mass, reducing fat mass, and maintaining normal blood glucose levels – not bad effects, hey!
My thoughts on Intermittent Fasting
As you know, I’m all about creating a healthy lifestyle that works for you, one that is sustainable, enjoyable and most importantly – healthy! There are so many ways to lose fat; jeez I’ve heard stories of people doing it by having pure sugar all day but is that healthy? Of course not. It’s about listening to your body and finding out what works best. It’s also about creating the healthiest environment for your body that you possibly can. I’m not scared to talk about fat loss as I know there are a lot of people out there who do want to lose fat, but we can’t get obsessed with fat percentage alone as the picture of health is much more than that.
But taking into account fat and general well-being, could intermittent fasting help improve those? Well, maybe…
I’m not saying I know all the answers or even that the science is bullet proof, (I don’t believe it’s ever black and white, or one size fits all) as we are discovering new things about our bodies every single day. But from what I have personally read so far, I’m at least intrigued to give it a go. Starting today, both my husband and I are going to try the 16 hour fast for 3 weeks and see what it improves. I gave it a go on and off for a week or two last month but not constantly enough to really measure any differences. Unfortunately I haven’t measured hormone levels, insulin sensitivity etc but body fat I have recorded, so I will update everyone on progress after those 3 weeks.
If you have any health issues, I would urge you to see a doctor before trying something like intermittent fasting to make sure you’re in the clear to do so. Just to clarify, I am not a qualified nutritionist, nor a scientist (!) so the purpose of this blog is purely to educate and allow you to make the decision for yourself.
One last thing I’d like to add is that although some may dub intermittent fasting a ‘diet’, I actually don’t perceive it as so, just like I don’t perceive carb-cycling as one either. That’s why I feel comfortable writing about it and giving it a try myself.
To me, I want to achieve the closest thing I can to pure health, which includes everything from energy to life longevity to mindfulness and a body that I love, BUT I want to do that whilst still living and enjoying my life to the fullest and not ever worrying about having a glass of wine or dessert at the dinner table! (Granted, I don’t order chocolate fudge brownie every time I eat out but I also don’t feel like I can’t if I want it). To me, that’s when happy balance really strikes. So, design your life as you want to, in the most healthy and happiest way that is. If eating 8 hours during the day instead of 11 is a significantly healthier and enjoyable route for you, then that’s no diet in my eyes.
I really hope you enjoyed this post, I put a lot of thought and love into how I could make intermittent fasting as an overview as simple but informative as I could! If you have any questions, comments or possibly experiences with intermittent fasting, then please do share it below with me and everyone else.