To read part one of my intermittent fasting experiment, click here.

When I started the Intermittent Fasting Experiment four weeks ago, I wasn’t sure how long I’d last.

I’ve always been a big breakfast guy, and for as long as I can remember, I’ve always eaten breakfast.

For many years, I used to think skipping breakfast was a sin, and that you’d lose all your hard-earned muscle mass within a few hours.

More recently, I’ve been open to the idea of my clients extending their overnight fast beyond the typical 10 to 12 hours if it suited their lifestyle, or if they weren’t big breakfast people.

The number one factor in body composition success will always be adherence to a plan, which comes from finding the right diet for your lifestyle.

Whether it’s the regular 5-6 meals a day approach, keto, high carb, low carb, vegan or intermittent fasting, the strategy that will yield the best results is the one that you enjoy and can stick to.

In part two of this experiment, I’m going to talk about the effect intermittent fasting had on different variables I was paying attention to and tracking in the past four weeks.

Hunger & Cravings

Whenever you start a new diet, it’s critical you always give your body at least two weeks to adapt.

I always find it remarkable how adaptable the body is, so don’t bail at the first sign of discomfort. Give your body time to adjust and find balance, and then draw your conclusions as to whether you need to change something or not.

Knowing this was useful in my first two weeks, as it did take some getting used to.

When you eat at similar times everyday, your body’s hormones start to function in a manner that makes us hungry when we expect to be hungry. So as you can imagine, every morning after an hour’s writing at 7am, I’d start to get hungry and think about breakfast.

Luckily, your body’s hormones are trainable. How you choose to prepare them for extended periods of fasting is up to you. You can either slowly push your first meal of the back by 30-60 minutes at a time, or you can jump straight in.

I went for the latter option, and switched from my normal 12 hour overnight fast, to 16 hours.

Eating breakfast at 11-11.30am at first was a little weird, and for the first 7-10 days, I was pretty much clock watching from 9am. After 10-14 days though, my hunger in the morning was diminished, I didn’t think about breakfast, and it felt normal to eat at the later time.

For the sake of this experiment, most days I tried to keep it to 16 hours, but there were days it fell a little shorter at 15 hours if I’d eaten later the night before, or even longer at 18 hours if I got caught up with something.

What I found regardless was that the 15 to 16 hour mark was the sweet spot for me. Around 15 hours is when I’d start to feel hungry, and at around 15.5 hours is when I’d want to just eat.

There could be a few reasons for this. Firstly, it may be the expectation of the fast coming to an end that triggered the hunger hormones. Second, and perhaps more likely, is that I’d typically finish my most creative and challenging work of the day by 10am.

Another interesting point to mention was that during the day, hunger was minimal, and I don’t think I’ve had any real cravings. This is despite going pretty hard on the diet these past 2-3 weeks in particular.

Although I started at 160-180g protein, 65-75g fats and 240-260g carbs, for the past few weeks I’ve been on 150-160g protein, 35-40g fats and 200-220g carbs. Normally, I’d be ravenous on that, but I’ve felt good!

Verdict: Better control of hunger and less cravings throughout the day

Mood & Energy

This is an interesting one in that after the initial 7-10 day adjustment period, where my mood was more up and down, I felt the same.

I don’t think fasting improved my mood, nor do I think it affected it either. During the eating window too, I noticed no real difference.

When I was researching different fasting experiments before trying this, I read about the improvements in energy most people experienced. Again, I didn’t notice any difference here at all. If anything, my energy has been less than normal, but this is likely due to the deficit kicking in (especially through more cardio), as well as higher work stress and not sleeping enough.

To give a proper review on this, it’d be worth monitoring my mood and energy during periods of lower training volume and maintenance calories.

Verdict: No change in mood or energy

Productivity

The initial reason for trying intermittent fasting was to see if there would be any improvements in my productivity and work output.

I talk repeatedly about my magic time of 6am to 9am in the morning, and if there was anything I could do to enhance this period, I’m all over it.

For this single reason, continuing a variation of intermittent fasting (which I’ll talk about later) is a no-brainer.

Instead of stopping after an hour of work, I can now power through and get an absolute ton of work done. My ability to get ‘deep work’ done and access the ‘flow state’ has been enhanced, and anyone who does any form of writing knows how good that feels.

Between 6am and 11am I can crank through my writing, my client emails and set myself up to just ‘deal with the bullsh*t’ in the afternoon. Knowing I’ve got all my ‘5% work’ done before breakfast is a great feeling and for this reason alone, it’s been a game changer.

In addition to the fasting, I’ve also introduced two other ‘tricks’ that have helped with productivity.

The first one is coffee. Nothing revolutionary by any stretch, but not something I typically drink in the morning. The way I’ve used it is that for the first hour, I’ll drink nothing but water. After an hour or so when concentration begins to fade a little, that’s when I’ll drink coffee to sharpen my focus and keep me going till 9am.

The second is something I picked up when speaking to Chris Knott on our RNT Fitness Radio Podcast: binaural beats. Before being exposed to these, I would repeat one classical piano song over and over, with my favourite being Nocturnes, Op. 9: No. 1 in B-Flat Minor by Frédéric Chopin.

Since switching to binaural beats, I’ve noticed a huge improvement in being able to ‘zone in’ on one specific task. You can find these easily on YouTube, and they work by playing waves of differing frequencies in each ear (use headphones for maximum benefit). This causes your brain to, as Chris writes in an article here, ‘harmonise in the middle, creating an optimum state for focus, concentration and relaxation.’

If you’ve never tried them, give them a go here.

Between the fasting, coffee and binaural beats, my work output has improved drastically, and this is exciting, especially given some of the projects we have planned on the horizon.

Verdict: Great improvements in productivity and work output

Training Performance & Strength  

A successful diet is all about maximising fat loss and maximising muscle retention. An integral part of this equation is your training, and your ability to maintain strength as much as possible while your bodyweight drops and the size of the deficit increases.

If you’re losing bodyweight but at the same time your training performance is tanking, you’re likely losing muscle at the same time.

For this experiment to be considered a success, it was essential that I could maintain my performance.

Much of this I believe to be your mind-set. If you think you’re going to be weaker, then you likely will. But if you approach the session with a progressive mentality, you’ll increase your chances of making improvements.

Now, many of the fasting protocols out there typically advise to train right at the end of your fast, and make your first meal your ‘post workout’ meal.

I like to train around 1pm because it breaks up my day nicely, so I chose to train after breakfast.

Throughout the past 4-5 weeks, despite dropping 10lbs, I’ve seen no loss in performance or energy when training, and have managed to set new personal records across all my main indicator lifts, keeping me on track for the ‘Road to Cali’.

On a few occasions due to scheduling, I did try weight training solely on EAAs before breaking my fast, and it was absolutely fine. No loss in strength or performance, and no real dip in energy either. This was interesting, and makes for a good option to have if I’m stuck in a situation where I can’t eat before training.

For cardio, I continued to do my LISS fasted as always, and have also done the majority of my HIIT sessions fasted (but using EAAs).

Verdict: No change in training performance and strength 

Bodyweight

My plan for the past 5 weeks was to drop about 10-15lbs (ended up losing 14lbs). This was never going to be a problem. It was just going to take some discipline when eating out, and reigning in the extra food that may otherwise sneak in.

In terms of dropping body fat, I don’t think fasting for longer helped speed the process up per se, but I do think it made it more enjoyable. The meals were bigger, more condensed, and I always felt satiated, which meant my temptation to veer off track was minimal.

I also think it has application when attempting to maintain your results, as the idea of a shorter eating window makes it easier to stay within calorie targets, provided you’re not bingeing.

Verdict: no difference in fat loss, but arguably easier to achieve the same outcome due to reduced hunger and cravings

Overall Thoughts & Future Plans

Intermittent fasting has been a great success…for me.

I think it’s important to clarify that just because it’s worked well for me, it doesn’t mean it will for others.

It’s important to avoid subscribing to any one protocol, and it’s why at RNT we’re not the ‘IF guys’, or the ‘keto guys’, or the ‘carb guys’. We’re the ‘whatever fits your lifestyle, goals and needs guys’. If that’s IF, then so be it! If not, then it doesn’t matter either. IF isn’t a magic bullet. The number one driver of body composition is adherence and consistency.

What IF has taught me is that no meal is indispensable. It’s broken the chains of the typical 5-6 meals a day, and taken me to a new level of productivity.

For my lifestyle, it works exceptionally well.

That being said, there are a few changes I’ll probably make.

1. Weekend Flexibility. I missed having breakfast with the family on the weekends, and so on Saturday and Sunday, I probably won’t IF. Instead, I’ll probably bump it up to 4 meals a day.

2. Muscle Building. By the same token, if your goal is purely muscle building, I don’t think IF is an optimal strategy. Your body thrives off being in a hypercaloric state on the daily, and eating is your most anabolic tool in your arsenal. If you really want to gain size, reducing the amount of time you have in the day to eat isn’t the best idea. I used IF during a ‘mini cut’, but as I transition back in muscle building, I’ll likely add another meal in later in the day. Trying to eat 3000-3500+ calories (clean) in 3 meals can be tough. I still want to maximise my magic time, so I’ll keep fasting in the mornings (even if it may not be as optimal for growth, being productive with writing is more important to me right now)

It’s also important to note that even if it sounds great on paper, you shouldn’t try intermittent fasting if:

1. You’re pregnant or trying to get pregnant. Fasting can influence your hormones, so if you’re pregnant or trying, avoid it. In general, many women report not feeling great on IF, so it’s always best to try it first and pay attention to your body’s feedback.

2. You’re new to diet and training. When you’re new to this, you want to learn basic habits to begin with, and learn how to pay attention to your own biofeedback before experimenting with fasting protocols.

3. You’re chronically stressed. Fasting is a stress to your body, so if you’re someone who’s always wired and stressed out, IF isn’t a wise choice for you. It’ll likely make your symptoms worse.

4. You’re trying to build maximum muscle mass. For the same reasons discussed earlier: it’s going to be tough to get your calories in, and you’re not using your most anabolic weapon, food, to its best potential.

5. You have a history of disordered eating patterns. This is a big one. Before you try any form of diet, work on fixing this first. If you struggle with overeating or binge eating, going long periods of time without food can set you up for potential disaster. I’ve seen this happen a lot, and even dealt with this after my first show, whereby I’d fast in the day, feel good about myself, and then binge at night and ‘think’ it was fine. When in reality, I was eating more than I would had I just followed a normal diet.