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Bulletproof diet and weight loss – my experience with The Rapid Fat Loss Protocol (RFLP)

This article goes like:

  1. Introduction and background Results
  2. Notes on my experience
  3. Bigger picture takeaways

(We decided to give you guys the results up front so we don’t leave you hanging for too long)


Back in April 2012 I was on the tail end of a debaucherous Fiji holiday (which was precluded by a stressful time at work so I hadn’t been taking v. good care of myself in the weeks leading up to it either - it happens from time to time!), being a fairly impatient person I felt like I needed a bit of a jump start to get back into the swing of things.

Enter the Bulletproof Diet “Rapid Fat Loss Protocol”…

Feeling fairly stress free on the tail end of the holiday the idea was to use the RFLP as a way to jumpstart my way back into a healthy physical state. The diet is basically a cyclic ketogenic diet with some systems thinking put into supplementation and food quality to ensure that it isn’t unnecessarily stressful on your body and also to address vitamin/mineral deficiencies that appear when you limit your diet to butter, Bulletproof Coffee and MCT oil. Cyclic ketogenic diets are pretty commonly used by bodybuilders in their cutting phase so I was confident that it would work, but I had never done anything that extreme so I was curious to see how I would respond.

I was pretty attracted to the thought of losing a LOT of weight in a short amount of time – its always nice to get to your goals in a shorter amount of time! Speaking of goals, at the time my initial thoughts on the process were:

  • Starting weight 87kg/191lb, from visual inspection my bf is ~15-17%, goal is to get it down to ~10% (note to self that I was probably being a bit nice to give my visual body fat assessment @ 15-17%)
  • Based on the fact that I'd just got back from a debaucherous week in Fiji (think beers and bad diet) I reckoned I would dump water down to 84kg/185b in a couple days.
  • Based on the last point my target is to get to 78kg/172lb with no muscle wastage.
  • I took some body measurements as a test – wanted to make sure I wasn’t losing all of my cms/in from my guns ;-) Not going to do much exercise apart from swing the kettlebells a bit in the mornings of my refeed day.
  • This was to avoid extra stress from training, and to do get a bit of a carb back-loading effect and avoid putting on too much extra weight on the refeed day.
  • I decided to do my first refeed after 3 days (instead of 5-7) so that I could ease into it and set up a bit of a routine... Based on the advertised 1lb / day fat loss (0.5 kg) I decided to try the program out for 14 days and see what happened.


Well I did lose a lot of weight! Especially the first couple of days when I dumped over a kg a day. HOWEVER this is all due to dumping water weight from drawing on my carb reservoir (for every 1 g of carbs stored your body stores 4g of water!!!). Think about that next time you see an ad on tellie promising 1kg / day fat loss in the first week, its not fat its just water – you will notice it because you’ll go to the loo about 100 times.

What really surprised me was that the weight loss continued at a pretty rapid pace throughout the 2 weeks, almost maintaining the 1lb / day rate talked about in the article. The experiment was a pretty considerable success considering that I wasn’t fully compliant with the protocol. See the table below for my scale measurements. (total weight loss ~6kgs in 2 weeks, pretty impressive. Note how pronounced the water re-gain is on the re-feed days!!!)

  • In terms of meeting my goals of not losing muscle mass during the experiment it was tough to be definitive.
  • Arm and chest measurements did not decrease much, but without a DEXA scan or something more reliable it is impossible to be sure.
  • My gut feel was that through all the BCAAs etc that the muscle mass loss was minimised if not eliminated entirely.
  • The photographic evidence below give some indication of this but again, its hard to be sure. My before/after pics are below. The before / after pics are probably the victim of lighting and angles working in favour of the before pic (the hulk shadows make me look like I was in a bit better shape than I actually was). However particularly the side on pic shows a pretty significant change.

My Experience

I’ve noted down some of the things that stood out to me throughout the process:

Overall it was a good way to lose a lot of fat in a short amount of time but it wasn’t without its challenges:

  • As of about midday the first day I was already craving my refeed day (look how happy I am in the pic!) but over time it got easier and then harder again.
  • Doing the full 5-6 days between refeeds was a bit tough for me to deal with, 3-4 days would be a lot easier for me to stick with over a longer term protocol. (lamb heart, lamb ribs, rice and a nice hot cup of bone broth to start the day!). Great Lakes Gelatine makes it really easy to whip up some bone broth. 
  • After the first couple days the thoughts of beer/junk food disappear and you end up craving healthy food (just one egg yolk… come on, please?). It ended up taking a bit of a toll on me psychologically (physiologically the absence of food was generally fine) and I ended up catching myself sitting for 30 min staring at the different recipes on the Nom Nom Paleo cookbook that I’d just bought for my ipad.
  • There were a few moments where the protocol took a bit of a toll on me in the form of:
  • Coldness – I would eat a truck-load more butter/MCT
  • Nausea I would have some liposomal gluthatione, wait 20 min then have a few charcoal tabs
  • Cravings – I found I could have a bit of unrefined sea salt sprinkled on butter which killed my food cravings pretty good. Having the same amount of butter with no salt didn’t do much. I can only think that I was missing some minerals that In general my compliance was good but there was a weekend down the coast which involved me eating a truck-load of oysters at the Narooma oyster festival which meant basically an extra refeed day.
  • I didn’t poo very much which was kind of weird (over share?) Also note that I didn’t follow the prescribed protocol exactly, I made a few modifications due to laziness or also trying to improve the protocol: I didn’t get the recommended bloodwork done (although I had done those tests within the previous 6 months). I would like to one day replicate the experiment using the talking20 product and see what kind of stresses manifest in my biochemistry during the experiment.
  • I didn’t take any Betaine HCL or other enzymes, I had be paleo/Bulletproof diet for a while and was already pretty well adapted to digesting the high amount of fats. I dosed up on Alpha-Lipoic acid on my refeed days to try to limit the amount of water re-gain (something i thought i would try from Tim Ferris’s “4 Hour Body” PAGG protocol. For a very small sample size it seemed to be effective!


  • There were a few things that this experiment taught me about myself generally and about how I respond to cyclic ketogenic diets: Deprivation is a good thing. After the end of the experiment all I wanted to eat were really healthy foods – I had a newfound appreciation for the nutritional value of the foods I eat (you have to maximise the benefit you get from the 1 day / week you’re allowed to eat).
  • In general (life lesson time) I think its good to deprive yourself of things from time to time so that you appreciate them. This is a tool I am going to keep in my toolbox for the inevitable time that I live like a hedon due to stress/holidays etc. In fact I actually felt pretty awesome after doing this type of fast so its something I have continued to do 1 or 2 days per month.
  • The diet was overall pretty easy to comply with, i actually enjoyed the fact that not worrying about dinner / lunch etc freed up about 2 hrs per day!
  • My girlfriend tried to do the same protocol and struggled more than I did. This was strange because she’s a fair bit tougher than me! A bit more research and talking to others about it (particularly Ivy from www.paleoinmelbourne.com.au) has led me to realise that girls are a lot more sensitive to the stresses of ketosis than guys are. My thoughts are that this type of approach needs to be moderated a bit if a girl wants to do it.


Questions or comments then let us know below :-)


Guest Author
Guest Author

This article was contributed by a guest author with expert knowledge in their field.

2 Responses


October 15, 2013

Hey Sonia,
My weight always goes up and down a bit. Unfortunately it is mostly my own doing and driven by times when i drink too much beer/cider etc :-( But such is life! Sometimes you let bad habits get the better of you!

I’m still around the same weight but i’m going through the healthy side of the life “cycle” at the moment. If i ever put a couple kg on then i do this one/two days a week till i get back to better shape.

One thing that i’ve learned is that girls and boys respond very different to some things. Ivy over at “paleo in melbourne” has done a lot of experimenting on herself with IF and has found that she does a lot better on a more moderated IF routine. Plus there is a whole bunch of research showing a different response like:

Boys are simple, girls have a whole extra layer of complexity with all the baby making bits!


October 15, 2013

Hi Leon. Thanks for writing this post. I’m interested to hear about any weight gained since then. If that was April last year- have you had much regain? Do you now eat low carb?
I’ve tried the bulletproof IF and after a month my whole weight loss halted from when I went paleo- So, kind of regret trying it!
I’ve now gained back too! So, more yoyo-ing to come perhaps. Cheers. S

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