What Is Intermittent Fasting?
Unless you’re waking nightly to go and get a midnight snack you’re already practising a form of short-term fasting.
What intermittent fasting does is take this incidental practice and makes it deliberate by splitting your day into 2 parts;
- A fasting period
- A feeding period
The concept is simple, you abstain from food and remain in a fasted state for a prolonged period of time before switching into a shorter feeding window.
Unlike many other diets, intermittent fasting protocols rarely specifies what to eat and instead focusing on when to eat.
There are several different intermittent fasting protocols that each have you split your feeding and fasting periods differently;
- 16:8 Intermittent Fasting
- 5:2 Intermittent Fasting
- Eat Stop Eat
- The Warrior Diet
- + More
This article will specifically refer to the 16:8 method of intermittent fasting.
16:8 Intermittent Fasting
The 16:8 intermittent fasting protocol is so named because of the way you split your day;
- 16 hour fasting period
- 8 hour feeding period
The most common set up is to begin faster after dinner, sleep through the night, skip breakfast and have your first meal of the day around lunchtime.
The reason you set it up like this is because you spend the majority of your fast asleep which makes the 16 fast a lot easier.
An additional benefit is that most social gatherings, dinners out and other occasions happen in the second half of the day which means 16:8 is also lifestyle friendly.
You see, if you fast for 24 hours either once or twice a week (as other protocols have you doing) you put yourself in the position of not being able to eat or for up to 2 days a week.
That means no brunches, no social drinks, meals out, date night dinners or anything else. Combine that with the fact that for 2 days a week you won’t be eating anything at all and you should be able to see why the 16:8 set up is much more lifestyle friendly.
If at this point you’re thinking great BUT…
- Isn’t skipping breakfast bad for me?
- Won’t fasting mess up my metabolism?
Let me help allay your fears.
The Truth About Fasting
Research (1) shows that after fasting (not eating anything) for 60hrs, resting metabolic rate (RMR) is reduced by only 8%.
Think about that, if after eating nothing for 60hrs your RMR is only decreased by 8% then missing a meal or fasting for a day will not put you anywhere near starvation mode or mess up your metabolism.
As for breakfast… research that supports the idea you ‘NEED’ to have breakfast has been shown to “lack probative value” and involve “biased research reporting.”
One study (4) showed that the belief we need breakfast outweighs any scientific evidence pointing to the same conclusion.
Additionally, a review paper (5) shows that existing evidence in favour of eating breakfast is weak and that studies show no cause and effect link between skipping breakfast and energy balance.
Ultimately it comes down to the fact that some people get hungry in the morning and function better with breakfast whereas others can forego breakfast to eat later in the day and function just as well.
The truth is for normal people, in normal circumstances fasting can be beneficial and at worst it’s just going to be a different style of eating with no negative effects.
Let’s look at how you could structure your day when using the 16:8 intermittent fasting protocol.
Example Fasting Day
The following template is what constitutes a typical 16:8 fasting setup, if it’s a workout day then you want to choose whichever workout slot works best for you.
Early Morning Workout (optional – choose 1) – If you choose to work out here in a fasted state you want to take some BCAAs to help prevent the breakdown of muscle mass during and after your workout. Ideally, you would also time your workout, so you can break your fast straight afterwards.
Morning – If you’re following the traditional 16:8 setup where you fast starting after your last meal and break your fast at around lunchtime you would not eat anything during this period, instead you can drink 0 calorie drinks like black tea and coffee or water (sparkling or still).
Mid-Morning Workout (optional – choose 1) – If you choose to workout here in a fasted state you want to take some BCAAs to help prevent the break down of muscle mass during and after your workout. Ideally, you would also time your workout, so you can break your fast straight afterwards.
Lunch – This will be your first meal of the day. If you’ve worked out before you want this to a medium to big sized meal being around 40 – 50% of your daily calorie intake. If you haven’t worked out yet it can be smaller.
Workout (optional – choose 1) – If you’re working out now then don’t worry about the BCAAs as you will have already eaten your first meal.
Afternoon Meal – If you decide to workout mid-afternoon or just prefer to eat more regularly then you can include a high protein afternoon meal. Something like an omelette with lots of veggies works well.
Dinner – This should be your biggest or second biggest meal of the day making up 30 – 50% of your daily calories.
Workout (optional – choose 1) – If you’re job or lifestyle mean you can’t workout until the evening it’s no problem, again you don’t need to worry about BCAAs as you will have eaten at least 2 meals prior to this point.
Post Workout Meal – If you work out at night then you may want to save some calories, so you can have a small meal post workout, what you have is up to you, but I recommend you include protein and some carbs.
Intermittent fasting is just one of many different ways to setup your diet.
When it comes to weight loss or gain, your total calorie intake across the day will be the determining factor, not whether or not you ate breakfast.
Which means for some people, like me, intermittent fasting becomes the primary way of eating due to the inherent dietary benefits, whilst for others it will be an occasional tool to help control calorie intake when on holiday or attending a social occasion.