Your 16/8 Intermittent Fasting Guide – All You Ever Wanted To Know About 16/8 IF
By Dr Joe
Wouldn’t it be great if you could adopt a simple fasting method like the 16/8 intermittent fasting and drop the pounds in weight and get lots more benefits at the same time?
Well, you are just about to find out if you can, right here on this page.
The 16/8 intermittent fasting is by far the most popular intermittent fasting method. It’s so popular that it goes by all sorts of nicknames like 16:8 IF, intermittent fasting 16 + 8, eat 8 hours fast for 16, fast 16 eat 8.
All sorts of names have been applied to this common method of fasting. It’s a bandwagon. You better hop on it, if you are thinking about it. Otherwise you will be missing out. Big time.
What is the 16/8 intermittent fasting?
Okay, it’s almost self-explanatory. You intentionally avoid eating for 16 hours in the 24 hours that make up the whole day and you eat in the remaining 8 hours of the day.
The 16/8 intermittent fasting is just as simple as that.
It’s not complicated. Anyone, absolutely anyone, can do the 16/8 intermittent fasting. There are 3 modes of fasting in general.
- Short fasts
- Long fasts
- Prolonged fasts
Short fasts are intermittent fasting lasting 12 – 24 hours
Long fasts are fasting episodes lasting for 24 – 36 hours
Prolonged fasts are fasting intervals lasting 36 hours to 1 week, 2 weeks or even 3 months.
Yes, people do fast for that long and they survive.
I am not exactly recommending prolonged fasts for you here. But as part of the learning process, it’s nice for you to know that prolonged fasts do exist. It’s not some theory. People do it.
As you would have gathered from the above description, the 16/8 fasting belongs to the short fast category.
16/8 fast is not a stretch of your innate human resources by any stretch of imagination.
Yes, for a beginner to fasting and for someone who has been used to eating 4, 5, 6 or 7 times a day, voluntarily abstaining from food over a 16-hour period might prove challenging at first. But it is not that hard, if you really want to do it.
In effect, for a 16/8 intermittent fasting, you stay off food for 16 hours of the day and you compress your eating window to the remaining 8 hours of the day.
And because the 16/8 intermittent fasting is a short fast, you can do it a lot frequently but within reason.
You should be looking to do the 16/8 intermittent fasting for about 3 – 5 times a week. You can do 16/8 intermittent fasting for 7 days a week but you don’t want to do that for too long.
Why fasting everyday is not your best plan?
One major difference between intermittent fasting and other forms of diets is that you can preserve your body’s basal metabolic rate. Your basal metabolic rate should not drop off when you do intermittent fasting correctly.
So, the ‘eat 8 hours, fast 16 hours per day’ for weight loss can lose some of its value, if you do 16/8 intermittent fasting every day for say 6 months continuously.
You will still lose weight. But the weight loss of 16/8 intermittent fasting may start to get marginal over time when abused.
What I am trying to say here is: we want to avoid going into the so-called ‘starvation mode’ where your body adapts to current eating pattern and reduces your basal metabolic rate correspondingly. Energy saving mode, that is.
You want to keep your body guessing. It won’t, if you get into a regular predictable pattern.
Don’t forget the keyword: Intermittent.
Why is the 16/8 intermittent fasting necessary?
Fasting can be done for health reasons or for religious reasons. Fasting for religious reasons is outside the remit of this blog, so I won’t be going there.
Intermittent fasting for health reasons concern us here.
There are obvious advantages of doing intermittent fasting not least for weight management. One of the easiest ways to lose weight and keep it off is through intermittent fasting.
But you have to avoid allowing your body to go into the energy saving mode (starvation mode).
The whole idea behind intermittent fasting regardless of the method of fasting you adopt is to get hormonal advantage. This protects your body’s metabolic health.
Everything begins and ends with the hormonal head-start that intermittent fasting gives to you.
There are 3 principal hormones you want to take advantage of when you fast. They are:
- Human Growth hormone
With intermittent fasting, your insulin levels drop, adrenaline levels go up and human growth hormone goes up too.
The interplay of all of those 3 hormones work synergistically to help you burn fat.
Intermittent fasting enables you to burn your immediate energy stores. I am referring to the glycogen stored in your liver and muscles. That has to be used up first before you access the stored energy – your body fat.
Insulin level getting low enables you to access the fat stores once you have used up your immediately available glycogen. Your body’s metabolic rate is fired up by the elevated adrenaline/noradrenaline and human growth hormone.
It takes 10 – 12 hours for the stored glycogen to be used up.
So, when you fast for 16 hours, you are essentially going to access and burn stored fat for only 4 – 6 hours out of the 16 hours fast period.
Remember, the first 10 – 12 hours of the fast period is a redundant period, where you are simply burning the immediate energy store – the glycogen. Until all of the glycogen is burnt, you will not burn the fat.
That is why I believe that the 16/8 intermittent fasting is about the bare minimum you need to do, if you want to shed fat and lose weight through fasting methodology.
How to do 16/8 intermittent fasting
I should mention that this method of eating was made popular by Nutritional Consultant, Martin Berkhan.
He christened it; Leangains protocol.
Martin is a maverick by all accounts who has a habit of breaking popular diet rules. He still gets results using the 16/8 method. He is quite muscular and has as little body fat percentage as you will find anywhere else.
See his picture below:
He exemplifies what is achievable when you adopt this method of eating. I should mention that Martin Berkhan did not achieve that 16/8 intermittent fasting result overnight.
As you can tell, he does incorporate workouts in his 16/8 regime. You are not going build muscle without some serious commitments to workout.
You will shed fat with 16/8 IF even if you don’t exercise at all (which is not always a good thing) but you won’t add to your muscle bulk without pumping some iron.
How do you start 16/8 intermittent fasting as a beginner?
In truth, you can manipulate the 24-hour clock to suit your lifestyle.
Fast for any stretch of the 24 hours in a day in any 16-hour window.
What do I mean by that?
Your 16-hour fasting period could be between 7pm to 1pm the next day, 3pm to 9am the following day, 12 midday to 6am the next day. A night worker who sleeps during the day can fast from 8am to 12 midnight the next night.
You get the point. It doesn’t matter what stretch of the night or day you use as your 16-hour fast period.
What’s important is: you fast for 16 hours at a stretch and you eat all your meals in the remaining 8 hours.
How you go about dividing the hours is up to you.
This flexibility is important because it means you can adapt the 16/8 fasting method into your lifestyle. Even if you are a shift worker like a nurse, para-medic, doctor; a trucker…
…a sales rep who covers a wide geographical area therefore travelling often, a pilot or air stewardess (or cabin crew as they preferred to be called these days) etc, you can still do the 16:8 IF.
Those categories of workers I mentioned above are the exceptions to the rule. Most of the population work 9am – 5pm and they have regular sleeping hours at night which nature designed for us to rest.
Now, for us regular folks making up the bulk of the population, it becomes a choice for you whether you want to fast at night until about 1pm the following day…
…or rather eat all your meals in the morning into the early afternoon and end 8-hour eating window earlier in the day.
I am referring to eating all your meals between 8am and 4pm, then fasting between 4pm and 8am the next morning, for instance. This would mean early start and early finish. This regime will work for someone who cannot skip their breakfast especially if their job is quite physical.
This 8am to 4pm eating window means you will be done with food commitments by 4pm and you don’t have to think about food anymore.
However, it may mean that, if you are someone who doesn’t go to bed early, there’s a chance you might be hungry by midnight when you want to go to bed.
Temptation to eat becomes high.
By far the most popular 16/8 intermittent fasting protocol is having your last meal of the day at 9pm and skipping breakfast the next morning to resume eating at 1pm.
Why is this popular?
It’s because it falls within the realms of having your 1st meal of the eating window at 1pm which is the regular lunch break for most office workers.
What that means is; your meals must be eaten between 1pm and 9pm. This gives you ample opportunity to do what you like and it falls in line with most people’s regular working hours.
Do remember, you can always shift these hours to suit you and your lifestyle. Don’t get hung up on fixed times.
One of the biggest advantages of intermittent fasting is high degree of flexibility built in. You can bend your hours any way you like. No one is holding a whip over you restricting you to do this and that.
Below are some suggested 16/8 fasting hours and eating windows.
If you work regular hours, please use any of the Schedule below:
|Fasting Hours||Eating Window|
|9pm – 1pm||1pm – 9pm|
|8pm – 12 noon||12 noon – 8pm|
|7pm – 11am||11am – 7pm|
|6pm – 10am||10am – 6pm|
|5pm – 9am||9am – 5pm|
|4pm – 8am||8am – 4pm|
|3pm – 7am||7am – 3pm|
For Night Shift workers, try the Schedule below:
|Fasting Hours||Eating Window|
|7am – 11pm||11pm – 7am|
|8am – 12 midnight||12 midnight – 8am|
|6am – 10pm||10pm – 6am|
|5am – 9pm||9pm – 5am|
The 1-2-3 formula to get you started on 16/8 IF…Follow This
Now do you have to jump straight into a 16-hour fasting period straightaway, if you are new to fasting? Absolutely, not. Remember I said, flexibility.
If you are new to intermittent fasting, start with a 12-hour fast, then the next day make it a 13-hour fast for 2 days, then next a 14-hour fast for 3 days. Give it a break for 3 days.
I call it the 1-2-3 formula. First run for 1 day, then a 2-day run, next a 3-day run, pushing “the boulder” up the hill by 1-hour for each run until you hit the target.
Resume your next fast with a 14-hour fast for 2 days, then a 15-hour fast for 3 days. Give it a break for 3 days.
This is all about building up your confidence, especially if you are someone who has been having 6 – 8 meals a day. This is important. You want to know you can do it.
And there is no rush to hit the target.
You also want to ease your appetite hormones like ghrelin into your new way of eating. Requesting your appetite hormones to behave themselves and stop bothering you!
After your second 3-day break, it’s time for the biggie. Now do your first 16-hour fast.
If your confidence waivers on your first 16-hour fast, then retreat to a 14-hour fast, then push it up by 1 hour each day. So, 14, 15 then hit the 16-hour fast.
Now give yourself a treat when you have done your first 16-hour fast. Hurray, you have arrived. It just gets easier from then on.
Once you get used to this 16-hour fast, you can extend to 18-hour, 20-hour and even 24-hour fast easily. It’s all about confidence.
Which brings me nicely to:
What should I eat after my 16/8 intermittent fasting?
How do you break your 16/8 intermittent fasting? Hmmm, there’s nothing magical about this, to be honest.
Remember, that word again? Flexibility. That’s the one.
Following standard good eating habits is the way to go.
Avoid highly processed foods, junk foods, refined sugar and foods with added sugar. If you follow that simple rule, you can eat just about anything.
If you are someone into carbs, eat your unprocessed complex carbs. If you are paleo or ketogenic guy, go for your standard paleo or keto meal that tickles your fancy.
It’s a good idea not to binge eat. Just be sensible with your portions.
However, if you are doing serious resistance training (which I advise you do) or any High Intensity Interval Training, then you may want up your proteins.
The Intermittent Fasting Workout Plan
Here’s what you should do as far as exercise workout is concerned when you’re doing the 16/8 intermittent fasting. If you follow this training schedule, you’ll reap huge benefits.
==> Exercise about 2 or 3 times a week.
==> If you exercise on your fasting days, do your workout towards the end of the fast period. The last hour of the fast period is best for fat burning.
==> Now if you are exercising intensely, you may want to protect your muscle mass. So, I’d say take branched-chain amino acids (BCAA supplement) about 30 minutes before your workout. See my article on BCAAs and intermittent fasting here.
It’s not mandatory to take BCAAs. So don’t sweat it!
==> Take bcaa supplements if you have them. If you don’t, you can easily compensate by having a high protein meal after your workout.
==> A good balanced meal of Protein (meat or beans, peas if you are a vegetarian or vegan) with lots of veggies and starchy carb will suffice.
==> Have your main meal soon after your workout. Prepare your meal in advance, so you are not tempted to go for takeouts or some junk food.
==> Eat as normal on fasting days that you are not exercising. You don’t need to exercise every fasting day, by the way.
Mix it up. You can do Paleo-style in your non-exercise days by having a meal of Veggies, Healthy fats and Protein (meat or beans, peas if you are a vegetarian or vegan).
When you mix it up, you will be carb cycling and that would be in keeping with what I refer to as the Depletion-Repletion way of eating.
Low carb days interspersed with high carb days but you should dose up on your proteins especially if you are exercising intensely.
A typical high carb meal will be:
==> 100 gm of protein (that’s about 4 palm size)
==> 100 gm of starchy carbs (that’s about 2 fist size)
==> 4 fistfuls of veggies
==> A handful of nuts or seeds
A typical low carb meal will be:
==> 120 gm of protein (that’s about 4 palm size and three-quarter)
==> 4 fistfuls of veggies
==> 2 handfuls of raw nuts and seeds
How many meals should you eat in your 16/8 intermittent eating window?
People are always concerned about how many meals to eat in the eating window once they break their 16/8 intermittent fasting.
Again, that word. Flexibility.
You can have:
- One big meal
- Or you can have two normal size meals
- Or one small meal and a bigger second meal
- Or if you really want to normalise things, you can eat 3 meals in your 16/8 eating window.
But always remember that the more meals you squeeze in, the higher your chances of over-shooting your calorie requirements for the day.
I personally eat one small meal of fruits and raw nuts for lunch and a bigger meal later in the evening. That’s me wrapped up for the day.
Those with digestive problems can have foods like bone broth, mashed potatoes, smoothies, soups, raw fruits, brown rice etc.
Try stuff out. There are no set rules.
Should I exercise during 16/8 intermittent fasting to lose weight?
The short answer is; yes, you should.
But you don’t have to. Exercise is not mandatory for you to lose weight on 16/8 intermittent fasting But it helps a great deal. You will still lose weight if you eat in 8 hours, fast for 16 hours IF protocol without exercise.
When you do add exercise to your 16/8 fasting protocol, it’s better to do it in the last hour of your fast and eat soon after.
Why is this?
Exercise sensitizes the muscles and makes them receptive to the macro and micronutrients made available from your meals. That’s why eating soon after your exercise sets the stage maximum nutrient utilisation.
In particular, protein synthesis, hence the high protein diet recommended when you exercise. This is highly protective of your muscles, preventing any muscle loss. Not only that, protein synthesis facilitates muscle building, if bulking up is your thing.
If you are going to exercise, then the right exercise that gets the best results for 16/8 intermittent fasting weight loss is high intensity interval training (HIIT).
Naturally, if you want to really build muscle, then of course you need to lift those weights.
And just in case, you are wondering if you will lose weight on 16/8 intermittent fasting, well take a look at this study.
The participants in that study are trained young men in their 20s and 30s who were already middle-level fitness guys. They were split into 16/8 IF group and Normal Diet group. The study ran over 8 weeks.
In essence, they didn’t really have much weight to lose.
But the study participants in the intermittent fasting arm still lost 1.6kg (3.5 lbs) of fat compared to the normal diet group who didn’t lose any significant weight at all.
Better still, these guys in the 16/8 intermittent fasting protocol still managed to gain 1.4 lbs of muscle. Not bad!
Something that happens in intermittent fasting is that IF increases the hormone, Adiponectin level in the body.
Adiponectin stabilises the basal metabolic rate. Higher adiponectin means your basal metabolic rate fires up.
This is a huge physiological advantage because it means you don’t go into energy saving mode (starvation mode) when you do intermittent fasting on this account. Cool!
Do I need supplements on the 16/8 intermittent fasting?
No, you don’t need to take supplements when doing 16/8 intermittent fasting. So long as you eat right, you don’t need supplements.
But if you are keen on the idea of supplements, then the only supplement you need for the 16/8 intermittent fasting is branched-chain amino acids (BCAA) supplement.
BCAAs are protective of muscle loss and are best taken on your workout days. You don’t need to take them when you are not working out. Take BCAAs on your workout days about 30 minutes before you commence exercise.
Here’s one BCAA supplement that works well and another one that’s very good for workout.
There’s a lot to be said about the 16/8 fasting method but this guide should be enough to get you going. Don’t hesitate. Give it a go.
Suggested further reading:
CEREALS That are Wreaking Havoc to Your Hormones, Your Energy & Your Weight (Avoid These)