My 30 Day Intermittent Fasting Challenge

intermittent fasting challengeSo a little while back I put together an (awesome) beginners guide to intermittent fasting.

IF has been a hot topic for years. Studies, blogs and personal anecdotes kept hyping up this bad ass eating strategy. People were jumping all over this head first.

So I wanted to see what it was all about.

The guide I put together is all research based. I dug deep, read a lot about it, asked a bunch of questions and summarized it nicely.

(You’re welcome.)

But if you’ve been following this blog for any time now, you know that I always take things with a grain of salt. And you should too.

So I figured it was time for another test. Another challenge.

And so for 30 days (straight) I decided to incorporate intermittent fasting into my life.

There’s just no better way to learn about something than to experience it for yourself. To immerse yourself fully. It opens your eyes to the little details and insights that you simply can’t learn from a book.

This is something I preach all the time. Try things. Don’t assume what you read or hear is the real deal. You need to constantly be testing things for yourself to figure out if they suit your body and your lifestyle.

Here’s what I learned from my 30 day Intermittent Fasting challenge…

The Details

In part 2 of my intermittent fasting guide, I listed off some of the most popular fasting protocols.

I had to choose one for this challenge.

Introducing the condensed eating window protocol.

Recall from the IF guide:

The idea [behind the condensed eating window] is to condense your food consumption period to a set number of hours, often between four to eight hours. This is your window of time where you can eat. The rest of the day (and night) you fast. This window can be changed to meet your schedule.

Pretty simple.

For this challenge I chose to go with an eight hour condensed eating window and a 16 hour fast.

More specifically:

1:00 pm – 9:00 pm –> Eat

9:00pm – 1:00 pm –> Fast

I set these hours based on my schedule (I work 8-5 full time). They could be different for you. Again…test.

The Meals

My eating window consisted of three fairly simple meals.

Meal one was at 1:00pm and made up roughly 20% of my total caloric intake. It typically consisted of meat and vegetables. Nothing too big. Low on carbohydrates. High(er) on protein.

Meal two was around 4:00pm and made up another 20% of my total caloric intake. More often than not it was a protein shake with an apple or two.

Meal three was around 8:30pm and was by far my largest and most filling meal – it made up the remaining 60% of my caloric intake. It was high in protein and moderately high in carbohydrates. There were some differences depending on whether this was a training day or not.

If it was a training day – I would train around 7 to 8pm (so I was training on a fairly empty stomach) – my final meal would be high in both protein and carbohydrates.

If it was a non-training day, my final meal would still be calorically high, but my carbohydrates were moderated. They were still there, but not nearly as high as on training days.

Here’s an example of a typical post-workout meal:

Fish. Eggs. Rice with some vegetables. A juicy salad on the side.

The reason for this set up is simple.

The first two meals of the day were purposely low both calorically and carbohydrate-wise to keep my blood sugar levels and insulin levels low. My last meal was the big one. The monster. It was perfectly timed after my workout when my body was most primed for nutrient absorption.

And I never went to bed hungry. It just worked well for me.

The Workout

For the purpose of keeping this article shorter, I won’t go into too much detail of my workout. If you’re interested in the details, ask below.

I did strength training twice a week using phase 3 style training I learned from my Visual Impact challenge. I kept my weights heavy, reps  low and rest periods long. But I was in the gym for no longer than 45 min.

One thing I definitely upped during this challenge is the amount of walking (or low intensity training) I did on my non-training days. I’ve found this to work really well when it comes to burning fat.

What I Learned

So what exactly happened? What changes did I experience? What did I learn?

Listed below are all the things I’ve discovered (mostly about myself) over the course of my 30 day intermittent fasting challenge.

My Hunger

I’ve lived my entire life with the mindset that breakfast was the biggest and most important meal of the day.

So I was worried a little bit that I’d be overwhelmed with hunger in the mornings. I went from having a huge breakfast in the morning to a single tall glass of water. My first meal got pushed back from 7am to 1pm. That’s a six hour difference!

Kind of a big change. But here’s the thing.

The hunger never came. From the beginning of the challenge I never felt hunger in the mornings. Not even close. I did consume a cup of coffee around 8-9am so that may have helped, but I never found myself wishing I could eat something.

It felt unusual. But good.

My Sleeping Patterns

This was probably the craziest revelation of the entire fasting challenge.

By switching to the three meal pattern and eliminating my early morning breakfast (which has been a standard part of my routine since I was born), my sleeping patterns got thrown completely out of wack.

They started to change from the very beginning.

In the very first week of the challenge I started to wake up early. Like 4am early. Every single morning.

It was very strange. I’d wake up, check my watch and see 4am on the dot every single morning. But I wasn’t tired. Not at all. I felt amazing. Energized. Fully awake.

The first few mornings I tried going back to sleep. On some mornings I succeeded. For most of them, I just ended up laying there. Wondering what the hell was going on.

But I kept with it. I went to bed around 11am every night. Eventually the sleeping patterns started to normalize. I started to wake up at normal times, but there were still random mornings where I had no use for an alarm clock (which is always nice).

So why did this happen?

I tried doing a little bit of research on this to see if anyone else has experience anything similar, but I found nothing.

My guess is that it has to do with the fact that I eliminated breakfast. My body has been accustomed to being fed first thing after rising. All of a sudden that feeding period was gone.

My body got confused.

It associated feeding times with my sleeping patterns. And when the feeding times shifted, so did the sleeping patterns. Remember that my first meal used to be at 7am (as soon as I woke up pretty much). Now, out of nowhere, my first meal got pushed forward by six hours.

And so my body tried to accommodate.

And thus came the 4 am rising time.

Eventually, my sleeping patterns stabilized. I started waking up with an alarm again.

You can see just how quickly the body is able to adapt.

I found the similar effect to be true during my experiment with losing weight. Within a day I dropped my caloric intake from 4,000 calories per day to roughly 1,200 calories per day and it took my body less than a week to adjust.

This is all good news.

It goes to show how quickly the body is able to make adjustments to any lifestyle modifications.

Note: The changes in my sleeping patterns may not necessarily be due to my changed eating times. These are just my thoughts. If you know of some research that explains this or if you’ve experienced something similar feel free to share your links or stories in the comments below.

My Energy Levels

If you recall from my intermittent fasting guide, fasting is supposed to have positive effects on your energy levels.

And I found that overall they did.

There were times near the beginning of the challenge that I felt woozy. Dizzy even. But those feelings quickly vanished.

On average, I felt like I was full of energy. Especially in the mornings. Never tired. Never fatigued.

I felt good.

I had tons of energy for training. Hitting the gym in a fasted state was a little weird at first, but it soon started to feel…normal. I never felt slow or sluggish. More about this later.

In the evenings I felt like I was ready for bed roughly around 11am every night. There were random nights where I felt like I was going to crash, but those were rare and sporadic.

My Weight

I was expecting to lose weight during this challenge.

I started off at 175lbs. Roughly 12% body fat.

My first week was kind of all over the place.

Even though I thought I was consuming a fair number of calories (especially from my last meal of the day), I wasn’t. Maybe it was a mental thing, but I definitely under consumed my calories on the first week.

And so after seven days I dropped 6lbs.

A little high, but keep in mind a lot of this was water weight due to the decrease of insulin levels caused by fasting.

So I decided to up my calories for the second week. I slightly increased my first two meals (not by much) and really upped my last meal (especially on training days).

And at the end of week two I was back up to 171lbs (gain of 2lbs).

Weeks three and four were fairly consistent. Loss of 1lb for each.

Here’s what my weight looked like over the course of the 30 day challenge.

Weight Fluctuation

Overall, the general trend is as expected – toward weight loss. Thirty days is a little short to get a full understanding of weight fluctuations, but it was enough to see that the research holds.

You will lose fat.

How much? Well that depends on a lot of factors. Some of them are in your control. Others aren’t.

The idea isn’t to place all your focus on what the scale says. Instead, focus on changes in your energy levels. Focus on how you feel. If you’re good in these categories you’ll be more inclined (read: motivated) to make better choices throughout. Weight loss will follow.

My Mind

Recall from the intermittent fasting guide:

When you fast, your body releases more of catecholamines (a stimulant hormone). As a result, mental focus is increased, productivity increases, and you feel like you can take over the world.

I felt this.

I felt sharp in the mornings. Super focused. My concentration was killer. I felt like I c0uld do more with less time (my boss loved this). It was an incredible feeling. (Coffee definitely played it’s part)

But there was something more important going on here.

I felt free.

Free of thoughts about food. Free of cravings.

I used to be hungry after not eating for 3-4 hours. I couldn’t get food off my mind. It controlled me. I felt powerless.

Even when I wasn’t hungry I had food on my mind.

Hmmm…what will I eat later?

Introducing fasting changed this. It took about a week or so to take effect, but I quickly realized that I was in control. I was in the driver seat.

By minimizing my fed state and introducing longer periods of the fasted state, I stopped feeling hungry.

I stopped thinking about food.

I felt free.

My Training with Fasting

I’ve already touched on training a few times in this post, so I won’t say much here.

I trained 4-5 times per week.

Two days of strength training coupled with skipping rope and kettlebell work.

A day or two of sprinting.

Nothing too far off from what I do typically.

Except for one thing.

I decided to add a lot of low intensity training into my routine.

I walked.

Walking is the perfect low intensity activity for initiating the fat burning energy system in your body. And, when coupled with fasting (especially when done after a long fasting period – in the morning for example), the effects are insane.

This is something I highly recommend whether you’re fasting or not.

Walk. A lot!

My Final Thoughts

This 30 day challenge really opened my eyes to the power of something as simple as not eating.

Introducing short periods of fasting into your lifestyle has effects that go far beyond body composition.

It changes the way you feel.

The way you think.

It teaches you the importance of listening to your body, instead of forcing things into it.

If this challenge has done anything for me, it has helped solidify my belief in the body’s incredible ability to adapt to change.

We think bad habits are hard to break. Impossible even. So we don’t even bother trying.

But that is all in your head. It’s all mental. Your body is capable of adapting very quickly. If you’re trying to instill a new, positive habit into your lifestyle, give it at least a week before giving up. Give it a chance. You’ll see just how incredible the body is.

So where do I go from here?

After the 30 days, I’ve slowly gone back to my old routine.

I’ve introduced breakfast again.

Not  because I don’t believe in the power of fasting. But because it’s something I feel works best for me.

Fasting still plays it’s part though. I follow the fasting routine at least two or three times a week. I throw it in after days I felt like I didn’t eat as well as I could’ve.

I give my body time to digest the foods properly. I give it a break from the fed state. And it rewards me by keeping my energy levels high and my mind sharp.

It’s all about balance.

About understanding that you need to work with your body.

Most importantly, I learned not to be a slave to my food. Eating every 3-4 hours is not a priority anymore.

I can now go through periods of not eating for 6-8 hours and feel absolutely fine with it. No hunger. No cravings. No guilt. Knowing that the fast is actually benefiting my body (instead of taking away from its performance) allows me to keep food off my mind.

It’s a beautiful feeling.

I hope you’ve gained something from reading this. I encourage you to try intermittent fasting out for yourself. It doesn’t have to be a full month. Even a few days will be enough to see some effects.

Remember that it’s all about trying things and seeing how your body reacts. This is what building a better body is all about.

If you have any questions, feel free to leave a comment below!

30 thoughts on “My 30 Day Intermittent Fasting Challenge”

  1. Srdjan, great timing for this article. I’ve also just started my version of IF. It’s a combo of Lean Gains and ESE done throughout the week. Thanks for pulling together some pretty great info. There’s a lot of info that people can really takeaway and put into their training plans for major fat-loss progress.


  2. Hey Srdjan!
    I’m LDS (many people call us Mormons) and in our church, we have a complete fast every month. I’ve been doing this since I was 12 years old (at 8, I started fasting only one meal). The key word is COMPLETE. Basically, the first Sunday of every month, I skip two meals, around 24 hours. I don’t eat ANYTHING, not water, not coffee (we don’t drink coffee anyway), not anything.
    I like your post here because it is outside proof of something in the Bible. In Isaiah, chapter 58, verse 8 (King James Version) it tells some of the rewards of fasting and literally says “…thine health shall spring forth speedily…”. I have experienced this too and agree that fasting, however it works for you, is a good idea for your health, among other reasons.

  3. Ive just finished studying sport at college, and I foun this article quite interesting. I find it quite hard to have the energy to work out in the gym. With being a girl, male decide to criticise me because I’m jot as strong as them. Did you find that with having a lot of energy in the morning, this woul be an appropriate time to go the gym, and work out? I alway feel tired when I comes to being healthy. Would this fasting help me have more energy to do a full workout without giving up and just leaving it? Is fasting good for health anyway, because it’s like your skipping meals. But not really, because your still having your calorie intake daily. Maybe this will help me to gain more energy.

    1. Hey Bethany, everybody’s energy levels peak at different times. I know for myself I have more energy in the evenings and so I train in the evenings. You just have to let your body tell you when.

      Intermittent fasting might be able to give you that energy that you’re looking for, but you’ll have to test it out for yourself to be sure. It’s definitely safe for your health (unless you have some conditions I’m not aware of).

      And don’t worry about what the guys at the gym think. You’re in there to build a better body, not compete with the guys 🙂

  4. Hi Srdjan:

    My day is very different from yours. I work out in the morning and sometimes I also play football (soccer) in the night. What would you recommend me? How should organise the meals?

    Is it a good idea to go to the gym without eating? The largest meal should be the one after working out?

    1. Hey Manuel – training in a fasted state (or going to the gym without eating) has some benefits so don’t worry about that. If you’re finding it difficult to train on an empty stomach try consuming a protein or amino-chain supplement directly before a workout.

      Your biggest meal should be after your workout so if it’s in the morning, have a big meal in the morning and two smaller meals throughout the rest of the day (you can set the times according to your own schedule).

  5. Very interesting results.

    We have been conditioned to believe that we need to eat breakfast, load up on calories as early as possible in order to either gain muscle or burn fat and other excuses.

    It goes to show that with discipline and following a proper regimen in your diet you can lean down and look good.

    The sleeping patterns though were a surprise.. but then again your energy levels were up which I guess balanced it out.


  6. I practise IF for years and I like it, but I can’t think anything but food, when I fast 🙂

  7. HI SP!

    At Last, i was waiting for your results for a long time now. THANKS!!
    Ive posted before about my results, so i wont bore you with that.
    A quick question, i exercise in the mornings so it is in my fasted state, is this a problem?
    I have not seen a difference in my performance as i usually, before IF i exercised before breakfast in any case.

    I learned through IF that what you eat is very important!!

    Another thing that IF helped me with is self control like you mentioned…but it helped me with a lot of things that i didnt have self control with.

    Its not as difficult as it sounds!!

    Hugo from South Africa

    1. Hey Hugo – thanks for your comment! Sorry for keeping you waiting so long with the results 🙂

      I think training in a fasted state can have many benefits, especially when it comes to boosting your HGH levels. One thing that a lot of people do when training in a fasted state is they use BCAAs (or some other sort of protein or amino-chain based supplement) right before their workout (see Alykhan’s comment). So if you’re seeing any stagnation in your training maybe give that a try.

      Thanks for sharing your thoughts!

  8. Great article. IF is also common in a lot of religions. Muslims fast for a month(ramzan time from 6AM-6PM). Hindu’s fast once a month citing religious reasons. I eat BF, Lunch and Dinner at specific times and it has really helped me concentrate more. But like you said, time and time again, a change/delay from the regular eating schedule makes me think only about food.

    Will start with the easiest option of skipping meals.

    Sri from India

    1. Sri – is it surprising then that countries like the US who don’t fast have such high obesity rates? Interesting…

      Let me know how your IF experiment goes!

  9. Srdjan,

    The protocol you followed is very similar to what I do. 8 hour feeding window (inspired by Lean Gains) beginning around noon to 1pm. 2 to 3 meals with the largest meal of the day being at night. Training varies but when I do it in the morning during my fast, I take BCAAs before and after. Cup of coffee at 10am with Stevia and cinnamon is HUGE for helping curb my hunger until noon.

    I love this routine and I also feel more energized and maintaining low body fat is almost effortless even with a few cheat meals on the weekends. One thing I’m definitely going to try is adding walking in the am on my off days. How long of a walk do you recommend?


    1. Alykhan – thanks for that comment. Did you experience any of those sleeping pattern shifts that I mentioned?

      I typically aim for a 30 to 45 minute walk on non-training days. Often I also added a 20-30 minute walk on training days (typically after my workout). Give it a try and see how it works for you.

      And you brought up a good point about weekends – I found it tough sometimes to stick to the feeding times depending on previous night’s activities. Did you shift your meal times during the weekend often?

      1. I didn’t notice any huge shifts in my sleeping patterns. I don’t think I ever woke up at like 4am early… I did notice that when I’m eating low-carb in general then I seem to require much less sleep (5-6 hours instead of 7-8) and still feel fine. I started doing 45 minute walks on off days also. I may try to incorportate the 20-30 minute walks on training days as you suggested.

        Sometimes on the weekends I shift my feeding window a few hours from 12pm – 8pm to 4pm – 12am or so. I actually find this easier to do because I don’t have to wake up early on the weekends which means by the time I get out of bed, get moving, get a good workout in, and maybe run an errand or two it’s already 2pm.

        1. I noticed that I didn’t require as much sleep either. Interesting. That’s the good thing about the weekends – the first meal comes quickly. Love it.

  10. I do a 24 (or a little less, i am not rigorous) on mondays and thursday (or recently on fridays because I like to train fasted) and I skip breakfast every weekdays. I am not ripped but IF helps to keep my weight in bay.

      1. The binge after the fast. I can”t resist, so I thought I train on fast days, becasue after trainig I’m not that hungry (or/and i can fool myself I build muscle with the food I eat after :-)) and it seems to work.

  11. Yes, my husband and I did the warrior diet 6 years ago, and we felt a bit week for the first few days, but in the warrior diet if your really starving your allowed to eat berries or pure protein, such as a small salmon stake or a small chicken breast, but after a while you get used to eating close to nothing, well after about a month we stopped, but we did loose weight. we went back to regular eating, but through out the years we find that naturally our bodies go back and fourth through this intermit fasting. I guess our bodies naturally want to eat this way sometimes. Anyway just thought id give my experience with it. Thanks for the article!

    1. Thanks for your awesome comment Dalia. It’s true our bodies are designed to go through natural periods of intermittent fasting. Think way back in the caveman days when we alternated between periods of feast and famine (either we had tons of food or we had none). In today’s world of abundance, we don’t experience that anymore. It’s a constant feast. And that’s exactly why I did this 30 day challenge…to give my body a chance to go back in time (kind of).

  12. I never heard of IF until I read about it on your blog. It sounds like a great idea. I’m going to give it a try tonight (I’ve been thinking about it for the last week). I’m doing the 24 hour fast starting at 4:30p, with the goal of fasting 1 day per week. I’m posting here, so that I feel some sort of accountability!

  13. Hey Srdjan,
    Great article. Very interesting results. Although I’ve heard of intermittent fasting, I’ve never really looked into it that much or understood it completely so thanks for the explanation!
    Just a few questions… After the 30 days, when you started introducing breakfast into your routine again, did you notice many changes within your body (because obviously your body had got used to this new routine)? As in, were you still able to go between meals without feeling hungry even though they were more spread out? Did you put on weight after switching back from fasting? I’m thinking about giving this a try, just wanted to make sure that my body would adapt positively making the transaction after the fasting period. Thanks again 🙂

    1. Hey Emily, great questions. I’ll be honest, re-introducing breakfast was really strange. My body had been so adjusted to being in a fasted state that it was unusual to get out of it. But, like always, the body adapts quickly. I didn’t gain any weight (or at least nothing drastic). I did start to feel more hunger between meals again, but I’ve realized that it was the types of foods I was eating that was dictating this, not the frequency or timing. Once I switched to Paleo style eating and cut out my carbs, those hunger cravings completely went away.

      I still use intermittent fasting, only in a more strategic fashion. If I have days where I don’t eat as well as I would like to (for whatever reason), I’ll fast the next day (as in, I won’t eat until 1-2pm next day). I’ve found this to work best for me.

      Just try it out and see how it works. Once you see how your body reacts to it you can make proper changes. It’s all a process. Let me know how it goes!

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