How To Use Intermittent Fasting For Weight Loss

“You should get on that intermittent fasting, bro…”

Yes, intermittent fasting is all the rage at the moment and it’s hard to walk into any gym without at least one person proclaiming it as the missing piece of the diet jigsaw.

And like all dieting methods, there is tons of false information out there from so-called ‘gurus’ looking to sell you a plan.

But this is a technique which many of my clients have used for years, and in truth it’s really quite simple.

So today I’ll show you how to use intermittent fasting for weight loss.

(And there’s nothing to buy! Yey!)

If you’re thinking of trying intermittent fasting to lose weight, you’ll find this article helpful.

Ready to get started?

intermittent fasting weight loss

The Next Big Thing

Check out this email I received from website subscriber Jennie.

“Hey Russ,

A friend of mine recently started doing intermittent fasting and she talks about it a lot. It’s something I’ve been curious of for a while, but some of the aspects sound too good to be true (basically, she can eat whatever she wants providing it’s within a certain time).

Can you explain how intermittent fasting works?”

I sure can.

If you prefer to consume your information in video format, watch below:

What Is Intermittent Fasting?

Intermittent fasting is a time-tested and long proven method of losing weight.

It may have only become trendy in the last few years, but bodybuilders have been using this style of dieting for decades!

It is based around the concept of eating your entire daily calorie intake within a relatively short ‘feeding window’, followed by a period of fasting where you consume no calories.

There are various time splits you can use for intermittent fasting, but my advice is to use one which works around your lifestyle. The most popular choices include:

  • 16/8
  • 14/10
  • 20/4

Over the years, I’ve found that most people get superior results by opting for a 16/8 approach (that’s a 16 hour fast with an 8 hour window for food). It’s not because a 16/8 unlocks some secret fat burning formula that other options don’t unlock, it’s simply because it fits around the lives of most people quite easily. But the other options are there if you prefer them instead.

Russ Howe personal trainer

Intermittent Fasting – The Good

Intermittent fasting tends to attract 2 groups of trainees.

Which one do you identify with?

  1. People who need structure and discipline in their diet in order to experience weight loss.
  2. People who already have a solid diet, but are in need of breaking a plateau.

If you look at any of the self-proclaimed intermittent fasting ‘gurus’ who have appeared in the last couple of years (no names necessary, you’ve seen the ads!) then you’ve probably heard about the selection of weight loss mechanisms fasting can produce.

And it’s true.

Intermittent fasting does appear to increase the activity of certain genes responsible for how much fat the body is able to burn, enabling us to burn more calories (and more fat) throughout the fasting period. (1, 2, 3)

Some researchers believe that when we finally break the fast, the activity of these genes is temporarily turned up even further, enabling greater fat burning. (4)

But the benefits of these activities are often way overblown, and present intermittent fasting as some kind of miracle diet which holds the key to the fat loss formula.

intermittent fasting results

It’s not true.

The main reason you’ll lose weight with intermittent fasting is down to something much simpler – it is a great tool for reducing your total calorie intake.

There are two reasons for this:

  1. By restricting your entire calorie intake to a short feeding window, you are less likely to overeat.
  2. Once you adapt to eating within set times, you’ll find it easier to avoid unplanned junk food snacks.

That second point is often overlooked, but plays a vital role in increasing weight loss results for most people.

After all, how many times throughout your working hours have you succumbed to the temptation of the vending machine (sometimes when you’re not even hungry!) just because it’s there?

The structure provided by intermittent fasting means you get used to eating only within certain times, and once you get past the initial few days (which are the most mentally challenging) you will find that temptation begins to wane outside of that feeding window.

Once your window starts, you are too busy trying to squeeze your daily calorie intake into that relatively short space of time, so again unplanned treats tend to go out of the window.

Calorie control is (by far) the biggest weight loss benefit of using intermittent fasting.

Legendary bodybuilding coach Jim Stoppani is a big fan of intermittent fasting. Here’s what he had to say:

Jim Stoppani intermittent fasting“I believe in enjoying life, but I’m also passionate about fitness.

Those two pursuits can be extremely difficult to balance.

That’s why I’ve been following an intermittent fasting eating plan for a while now. It lets me eat the foods I want (within reason, of course), while maintaining my shredded physique.”

how does intermittent fasting work

Intermittent Fasting – The Bad

Like all dieting trends, intermittent fasting has attracted it’s fair share of bogus advice.

One of the biggest pieces of misinformation is actually referenced in the customer email at the top of this article.

The idea that you can eat whatever you want, as long as it’s within a certain time frame, is incredibly popular among gym goers despite having absolutely no foundation of truth.

And when you put it into context, it sounds as ridiculous as it is!

Of course we can’t just gorge on 10,000 calories and magically blast body fat into the space time continuum just because we did it inside our magical 8 hour time frame…

10,000 calories is still 10,000 calories!

One of my old buddies used to believe this, too.

And after coming off a junk food diet to trying intermittent fasting he initially dropped a few pounds, before starting to push the envelope under the guise of “experts say I can eat whatever I want as long as it’s in my feeding window.” He piled all the weight back on and ended up heavier than when he started.

Not good.

does intermittent fasting work

The general rule of calories in versus calories out still applies.

Because despite the fact that intermittent fasting may influence some additional fat burning effects within the body (as explained in the previous section), these are completely overshadowed by the number one rule when it comes to weight loss: you must consume fewer calories than you burn in order to lose weight with any diet. (6)

This is by far the biggest misconception surrounding intermittent fasting, but there are some smaller myths out there, too.

One of these other myths you’ll hear about IF is it’s ability to increase oxygen supply to muscles during exercise.

Research does indicate an increase, and this initially created a big buzz around IF because it’s the same thing endurance athletes are trying to achieve when they take illegal substances (more oxygen to working muscles = much better performance), but fasting won’t create anywhere near the same increase in oxygen supply as an illegal drug. (5)

The final myth I regularly hear is that intermittent fasting can be used to reverse the effects of type 2 diabetes.

This is bogus advice.

A 2015 study published in Diabetes Care found that fasting (in this case, participants skipped breakfast each day) impaired insulin response. Making your overall diet healthier and partaking in regular exercise will help you to begin to manage diabetes, not fasting. (7)

intermittent fasting

Intermittent Fasting FAQ

Q. Can you use intermittent fasting to build muscle?
A. While there is a growing body of research to support the use of intermittent fasting for weight loss purposes, the landscape isn’t so fascinating when we look at using intermittent fasting to build muscle.
This is largely because in order to gain size we must put ourselves into a calorie surplus, and this makes IF a little impractical as we’d be trying to eat more food in less time.
It won’t do you any harm, but it’ll leave you feeling stuffed.
I believe intermittent fasting is best used as a fat loss method, because it plays to it’s biggest strength – calorie control.
Q. When should my feeding window start?
A. In a perfect world, your feeding window should begin the moment your workout ends. This allows you to get some quality post-workout nutrition to your tired muscles, so they can begin the recovery process as soon as possible.

We don’t live in a perfect world, of course, so I expect there will be times where you need to compromise.

So, as a priority, schedule your feeding window around the times of day when you are most hungry (i.e. the times you actually enjoy eating) to get maximum results.

If you prefer eating later in the day, but you have a busy schedule which requires you to hit the gym first thing in the morning, it doesn’t make sense to start your feeding window at 9am and then leave yourself hungry all night when you typically like to eat. This increases the likelihood you’ll overeat and defeats the whole point of intermittent fasting. In this situation, you’d simply train in a fasted state, man the f**k up and keep your feeding window later in the day.

You’ll be fine.

Q. What is the best way to start my fast?
A. Protein is the most filling of macronutrients, so a great way to end your feeding window is to consume some slow-digesting protein (try cottage cheese, or a casein protein shake). This will keep you feeling fuller for longer as you head into your next fasting phase.
Q. Is sleep included in my fast?
A. Yes.
Q. What is the best way to ease myself into intermittent fasting?
A. The prospect of a 16 hour fast (if following the 16/8 split) can seem daunting at first.
But there’s no need to jump in at the deep end.
Start yourself off with a 12/12 (i.e. 12 hour fast, 12 hour feeding window) and see how you go. Then move it up to a 14/10, and eventually a 16/8. You can play with the system and find one that works best for you, but the general rule is that the shorter your feeding window gets, the better you will be able to control your calorie intake.
Take your fast too long and it can have reverse effects – I’ve known a few gym goers who jumped in with a harsh 20/4, and they found that by the time their feeding window opened they had gone beyond acceptable hunger levels and triggered something I call last supper syndrome, whereby they wanted to smash everything in their fridge. HA! I’ve been there…
It’s all about balance.
Q. Can I use BCAAs during intermittent fasting?
A. Yes, but not during your fast.
One of the common myths surrounding intermittent fasting is that you should drink BCAAs during your fast to provide you with ongoing energy and to prevent muscle breakdown.
This is false information, and is inadvertently breaking your fast.
Sure, your BCAAs may say they have zero calories, but this is because FDA rules state that supplement manufacturers are not allowed to list calories from free form amino acids. Bottom line? Your BCAA supplement is not really zero calories.
Also, research does not support the notion that fasting will cause muscle loss anyway. (2)
People often also make this mistake when drinking BCAAs before fasted cardio.
Q. Can I use other supplements during my fast?
A. Only if it has zero calories. Caffeine can be quite useful for keeping your energy levels up.
Q. Do you need to do intermittent fasting every day to get results?
A. No.
As the name suggests, this technique is best used intermittently.
Sure, there are extreme practitioners who swear this is the only way you should live your life. But every diet corner of the fitness world has extreme believers (CrossFit, Atkins, whatever bulls**t Gwyneth Paltrow is selling this month, etc).
One of the great things about intermittent fasting is that you can test the water by applying it one or two days a week to see if it suits you. You only have to look at the popularity of The 5:2 Diet (which is a form of intermittent fasting) to see that it’s definitely not “all or nothing”.
Q. What foods am I allowed to eat during my fast?
A. None. It’s a fast.

does intermittent fasting work

Intermittent Fasting – Final Thoughts

Hopefully, by now you have a good idea whether intermittent fasting is something you can see yourself doing or not.

We’ve been through all of the benefits of intermittent fasting, as well as the drawbacks, and even covered the myths.

But the final decision rests with you.

Because while intermittent fasting does indeed come with it’s own set of benefits (and many of my clients enjoy using it to lower their body fat percentage), it is only really useful it you are able to fit it into your lifestyle.

After all, the best diet is the one you can stick to.

If you’ve enjoyed my in-depth article on how to use intermittent fasting for weight loss, drop a like on it below and share it with anyone it may help. Get me on Twitter with any questions.


  1. Pilegaard, H., et al. Effect of short-term fasting and refeeding on transcriptional regulation of metabolic genes in human skeletal muscle. Diabetes 52:657-662, 2003.
  2. Hildebrandt, A. L., et al. Exercise attenuates the fasting-induce transcriptional activation of metabolic genes in skeletal muscle. Am J Physiol Metab 278:E1078-E1086, 2000.
  3. Mattson, M. P., et al. Beneficial effects of intermittent fasting and caloric restriction on the cardiovascular and cerebrovascular systems. J Nutr Biochem. 2005 Mar;16(3):129-37.
  4. Trabelsi, K., et al. Effects of Ramadan fasting on biochemical and anthropometric parameters in physically active men. Asian Journal of Sports Medicine 2(3):134-144, 2011.
  5. Stote, K. S., et al. A controlled trial of reduced meal frequency without caloric restriction in healthy, normal-weight, middle-aged adults. Am J Clin Nutr 85:981-988, 2007.
  6. Swinburn B., et al. Increased food energy supply is more than sufficient to explain the US epidemic of obesity. Am J Clin Nutr. (2009)
  7. Jakubowicz, D., et al. Fasting until noon triggers increased postprandial hyperglycemia and impaired insulin response after lunch and dinner in individuals with type 2 diabetes: a randomized clinical trial. Diabetes Care. (2015)

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