Back in 2009, I became aware of a Mr Martin Berkhan, while reading an article on Elite FTS called “To Feast or not to Feast” I was entranced by his crazy notion of going without food for a whole 16 hours. Skipping breakfast?! Surely not!

During this time I was undergoing my initial transformation and as a result of the circulated information at the time, I was religiously eating breakfast. The meal content varied, but I made sure I was waking up to some sort of protein hit, without fail and this article had just blown that out the water.

“You mean I don’t wake up as a muscle burning furnace that can only be quenched by washing down half a litre of whey?!”

I tried Leangains style IF (16/8) for a few weeks shortly after reading the article and perusing Martin’s site. I timed this with the start of an internship during a summer break at uni, I felt it would serve as a convenient solution to having to get decent meals in while constrained to the confines of the office canteen. I decided to set my 8 hour feed from 4-5pm until around midnight, leaving my evenings filled with some pretty calorie dense feeds. My weight-loss continued but it became effortless, I actually struggled to fit the calories in initially.




This experience had me sold on the benefits of IF, I needed a brief period to adapt to it (which wasn’t too pleasant) but afterwards it was a breeze compared to smaller, more frequent meals.

Since then I’ve experimented with many kinds of fasting ranging from 14-48 hours in which I abstained from food. Each method has distinct pros and cons and obviously the difficulty associated with adhering to a fast becomes exponentially greater when you start to encroach on the 24 hour mark. This said, the commonality is larger feedings and these are generally linearly related to the length you decide to fast.

While this obviously has merit, I think there is an unspoken dark side to fasting, one which left unchecked can become a significant problem down the road.

I’ve always observed a theme when implementing a given fasting protocol for extended periods of time. When I first implemented the 16/8 schedule (after a week or so), it was sooo easy to go until 12-1pm without food, it became habit, this was consistent even with ADF (36 hour fasts) – hard for the first week or so then a definite cruising period where you barely noticed not eating for your chosen period of fasting.

However, I started to notice that after a month of two, previously absent hunger would rear its ugly head during the fast, I started to wake up hungry and occasionally remain hungry throughout the fast. I’d soldier on until my scheduled meal time and often be left unsatisfied by meals which could even extend to 2000+kcal. It was like I’d forgotten what is what like to feel “full” and I’d trained myself to be able to handle huge loads of food in one sitting.  Scanning my food logs I noticed over time that I’d been making my meals larger and larger to contend with this increasing tolerance to large bolus meals. What’s more, my focus on food began to increase. Initially, I enjoyed how IF could allow you to forget about food during times of the day and increase your productivity as a result, however, now I was sat at my desk coping with hunger pangs that no amount of coffee and water could satisfy.

This may sounds like I’m demonising IF as a terrible schedule to implement but my feelings towards it are quite the opposite – I think it’s a fantastic tool and I still structure most of my days in an 16/8 style.

However, I do think the standard recommendations gloss over the downsides of fasting:
1) an increased level of hunger during the fast that seems to appear after some time on fasting protocols, previously hunger-less fasts become times of intermittent hunger. 

2)  A decreased satiety signal from meals including thousands of calories and a tendency to increase the size of meals.

3)  A tendency to over-eat at meal times, some experience ‘runaway hunger’ that leads them to exceed their allowed calories and macros for the day.

4) A sense of ‘entitlement’ to larger meals as compensation for the sacrifice of skipping breakfast and perhaps a disproportionate amount of ‘junkier’ foods included within the large meals. 

5)  Blood sugar peaks and troughs associated with large feedings, sluggish afternoons and wired mornings. Huge meals cause a sleepy sensation with even the best insulin sensitivity

6) Digestive issues caused by eating progressively larger meals and placing unwanted stress on the GI tract. 

You may experience none of these, you may experience all and more. This is a very individual thing and it will require you to pay attention to your own responses.

Generally speaking however, most will start to adapt to the large meals, by the very nature of some IF protocols, you have to fit a very large quantity of food into a narrow timeframe which, initially, will involve eating past satiety. Because of this, eventually you arrive back at this entropic medium that you were at before IF, eating a meal and generally noticing some hunger 4-5 hours later – not so convenient any more.

So what can we do about this?

Through trial and error, I’ve fallen upon a very simple schedule fix that allows you to implement IF for long stretches while mitigating many of the above issues. I first used it by accident, on a day I was scheduled to follow my regular fast I woke up with potent hunger, worse than usual.  I decided to ditch my 1pm planned meal time and eat a modest breakfast. What I noticed was a powerful suppressing effect on hunger, it disappeared until past 1 o’clock at which point I was able to eat another small meal to keep hunger at bay. Intrigued, I maintained this schedule for a few days and actually started to enjoy the habitual benefits of breakfast, it got me up earlier and I developed a very enjoyable morning routine.

After a month or so of this, I decided to try fasting again. The result was similar to when I tried IF for the first time, I breezed through 16 hours with no hunger at all.

Since then, I’ve used the above consistently, cycling between IF and more frequent feedings with great success and feel I actually enjoy the best of both worlds. When I switch to more frequent meals, I re-learn being content with meals of 500-600kcal such that when I do switch back to IF, the same caloric load allows what feel like very decadent feedings. I’ve observed that IF is like a sliding scale with most people, it starts very sensibly with slightly larger meals and slowly descends into a lesser controlled feast-fast pattern, an attitude to food that I think we should always try to avoid.

Some practical advice:
1) Periodise your nutrition: I like to use IF for 8-12 weeks followed by a block of 6-8 weeks where I’ll eat more frequently. This is personal preference and you may prefer blocks of different length but I find this to be a good balance. There is the added advantage of being able to eat some of the breakfast foods that IFers often forgo – pancakes and syrup anyone?

2) Intra-week change: Another option would be to switch things up within the week, eat breakfast on weekends and fast until lunch during the week or vice versa. Maybe even use an eat-stop-eat style approach that includes 1-2 24 hour fasts. One method I use while in a block of IF style eating is to fast untill midday during the week but slightly longer on the weekend where I’ll train with BCAA around noon and eat at 3-4pm. Some find ghrelin entrainment to be an issue with this approach (you tend to feel hungry at times you’d normally eat, so this method won’t be for everyone)

3) Use the RPH scale: one way I use to determine when to switch between phases is to use a rating of perceived hunger at 4 points in the day. I’ll rate how hungry I am upon waking, at midday, at 4pm and before bed. My goal is for these numbers to be as low as possible and I’ll pick my approach based on this:

For example, I may notice, while in a block of frequent feedings that my morning RPH is gradually    dropping and my hunger may be higher before bed. I’ll use this as a cue to switch to an IF regime, pushing calories back toward the end of my day to match my hunger patterns. I rate my hunger out of 10 at these points and note it in my training log, I’ll also calculate an average for that day which is useful to spot trends and patterns.

4) Experiment with carb timing: One thing I noticed when switching to eating breakfast is that certain macro-nutrient combinations will create a sleepy sensation and actually stimulate hunger. I’ve found personally that breakfasts of <500kcal and <100g carbs to be the best for me. One commonality for those that use IF or Carb Backloading is a significant mental fog after eating their carb-laden meals, I’ve actually noticed that I respond very well to an equal spread across the day which a focus on pre/post workout.

5) Consider your goals: there is some research out there to suggest that for muscle gain, IF may not be optimal. I’m not saying it won’t work – it will, more that if you can easily maintain a schedule of more frequent meals that you may be shortchanging your progress somewhat just so you can fit in larger meals at night. Don’t use a meal schedule for hedonic reasons or because its popular, tailor it to your goal. Conversely, IF is a sensible option for fat-loss.

6) Tune into your rhythm: I’m hungry at very fixed times in the day – 7am, 12pm, 4pm and 7pm. There’s a +/- variance of an hour but generally these run true. Everyone will have their own pattern of hunger. Pay attention to this and tune your meals to this. My 7am hunger is the main indicator usually, if this passes quickly I’m good untill 12pm usually, if it lingers I reach for the eggs and a frying pan.

7) Frequent but infrequent: Even when using more frequent meals I still stick to 3-5 meals per day and I’ll also often skew caloric intake to the end of the day, this fits with my hunger patterns. The key is that I’m not switching to 8-10 meals per day, I still want to keep the meals of a reasonable size as I’m not convinced that very frequent feedings do anything for adherence.


So there it is, a slightly different, more practical guide to ways you can optimise your eating schedule to your own physiology and goals. Do you use IF? What are your experiences with it? 

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3 responses to “IIFYL – Intermittent Fasting

  1. good article man, personally, everyone things fasting is the be all and end all, all i think about when fasting is food, and food and more food until i get that big amount of food, which, does not fill me up one bit leaving me counting down the clock to my next meal, not a good way to live and a added stressor i do not need, finding it hard to transition back to breakfast as it seems like its the “devil” and fasting is the ONLY way to stay lean

    1. Definitely – people overestimate fasting whereas it’s biggest contribution is the behavioural element. Especially after seeing Berkhan’s clients getting shredded it’s easy to think it’s the only way

  2. Brilliant article, going back over I can’t help but feel that Berkhan was susceptible to confirmation bias about IF without being honest about it’s shortfalls. Blindly following any protocol is stupid whether it’s 2 meals or 10. Can I ask what research you were referring to with regard to IF not being optimal for muscle gain?

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