Results of my ketogenic intermittent fasting experiment

Last winter, i had been watching some youtube videos by the hodge twins on intermittent fasting and felt inspired to try it myself. In a previous post, i talked about the routine i created and explained why i thought it was a good idea, based on months of research and a little personal experience prior. I decided to approach my intermittent fasting routine like a science experiment, and devoted myself to being as consistent with the routine as possible, as well as tracking my weight every day.

Here is an annotated plot of the weight data i collected using google fit:


I aimed to lose 25lbs but lost 27. I was pretty impressed with the fact that i could still lose weight at this pace, years after losing 80lbs doing a semi-lazy ketogenic diet and having the effort required to lose more weight exceed my willpower under that way of dieting. I lost weight at almost twice the speed doing intermittent fasting.

Some interesting things happened along the journey, though.

The initial high!

Just like when i went from being a high carb vegetarian to a low carb meat eater, i experienced a druglike high that lasted a week, and had extreme optimism for this experiment. I think that most people have these feelings when starting a diet, and then reality sets in once the diet requires real work/change. This is a huge bump in the road that throws most dieters off.
But.. having prior experience, i was ready for this.

The biggest enemy of any diet is your peers

Having done ketogenic dieting before, i understand that a hunger pang or growling stomach is the body’s way of protesting what you are trying to do, not a death threat. Being adapted to running on fat, these sensations can be ignored with masterful ease; so that was the easiest part to deal with. The real problem with such an odd diet is the way people around you eat.

Many times, i’d be offered food and would reject it or have to put it in tupperware for later consumption; and socially that can be awkward, but it was well worth the price. After a few weeks, the timing of meals became a habit instead of a struggle, requiring very little willpower, and this routine was on cruise control.. but the social problem was persistent and i found myself explaining what i was doing quite often, yet still had people inviting me to dinner or offering snacks anyway. I just got used to saying ‘i appreciate it, but no thanks’ rather than bothering to explain my experiment.


While doing intermittent fasting, you will quickly realize how often most people eat snacks. It’s hard enough to follow a low carb diet around the unaware, but I found it socially alienating to have to constantly reject food in the workplace on top of that. However it was empowering because I didn’t ‘need’ to snack since my body was doing a hell of a job using itself as a fuel source between meals. Intermittent fasting actually reduced my appetite so much that the idea of having a snack in the middle of the day wasn’t interesting at all, even if it was something i liked.

I understand that people snack because a carb heavy diet lends itself to a blood sugar level roller-coaster that requires constant intervention. Being in a state of heavy ketosis really puts you on another playing field though. You will exhibiting what appears to be godly, legendary, inconceivable levels of willpower to the average carbivore. A carbivore will never understand this. Your metabolism and theirs are on two completely different operating systems. Just don’t expect them to understand.

On the upside, you enjoy the f*** out of those 2 meals you eat every day. Food tastes amazing when your body NEEDS it. If you’ve ever had issues with overeating, you know exactly what i mean. Overeating dulls the senses and constantly has you chasing the sensation of the first bite and you will sit there and keep shoveling the ice cream hoping that feeling will come. Under intermittent fasting, your palate is always very sensitive and you don’t dull it out until you break the regimen. Everything you put in your mouth is amazing.

The second hardest part is your own neuroses!

If i could do it again, i’d not step on the scale every day. There is a psychological toll to this – on the days where you do not see results, it can make you second guess yourself. I immediately had a 1 week stall period and was questioning my routine, but decided that in the name of science, i had to continue. I had a windfall of weight loss, got overconfident, over-ate, and stalled again, then got strict again.. then got a little lazy.. and so on. The truth is, tracking every day made me kind of nutty.

One thing i learned is that i do not have full control over my metabolism. I can flip the switch to ‘lose weight’ by doing calorie restricted intermittent fasting, but my body will consume it’s own fat at times and rates i cannot predict. I can be completely mechanical and consistent with calorie counting and timing and not lose a single pound for weeks. Then the next day i can see a sudden drop of 4 pounds. Some days i would gain 2 pounds for no reason at all, then drop it over the next 3 days. There was no pattern or correlation.

So.. I only tracked daily as a means to benchmark ketogenic intermittent fasting against regular ketogenic dieting. It’s not something i recommend.

Effects on the body

During this routine, i experienced a few physical and mental changes:

  1. Low blood sugar symptoms after blowing 300-400 calories at the gym every day. Not a surprise at all, as Gluconeogenesis only happens at so fast of a rate, and i was in a pretty serious caloric deficit. My body eventually decided to stop supplying so much energy while at the gym, and my workouts suffered. 3 months in, i decided to do a small modification and eat approx 200 calories 1 hour before gym time. This ended the light headness and weakness and also didn’t slow my weight loss at all. I would just eat 200 calories less later.
  2. Insanely high ketone production. You’ve heard of keto breath and dinosaur piss? I experienced something i’m going to call nail polish remover whiff. I would randomly smell nail polish remover/acetone as if i had just taken a big whiff from a bottle. I must have had ketones oozing out of every pore. Wow. The weird thing is that the ketones never showed up on a ketostix. I believe that eating almost 4 years the low carb way has made my body efficient as using ketones though and not seeing them on the stick is no surprise.
  3. Sorry for the TMI, but this comes up a lot in low carb groups, so it’s worth a mention. When you are calorie restricted, your body becomes astoundingly efficient at burning food as fuel, and as a result, you can poop as little as once a week. The first 4 day lapse i had, i was thinking a medical emergency would soon come, but nope. This is completely normal while fasting. You’re not gonna die.
  4. Low energy all around. Your body really does not like losing weight for an extended amount of time. If dialing up the appetite hormones does not work, often times the body will attempt to conserve energy by dialing down thyroid hormones. The lower your body fat percentage, the harder it is for the body to access it’s fat and turn it into energy also. I had quite a few days where i felt pretty ‘meh’ and had to force myself out of the house. I lost the battle against this ‘meh’ after losing 80lbs on regular keto, but intermittent fasting gives you another edge against the ‘meh’. It allows you to go further into insanely low bodyfat percentages if you want. You just have to be patient and accept it as a consequence of dieting.  If it’s really bad, you can up the calories a little and you will still lose weight.

Effects on weight training


Oh boy, oh boy is there a lot of bullcrap on the internet about losing weight while gaining muscle. Proponents of intermittent fasting will point out that human growth hormone increases during fasting, insinuating it will help muscle gain. Then there’s the carb fueled bulkers who will say that your body will immediately start eating muscle the second you start restricting calories. As usual, the truth is somewhere in the middle. At least it was for me.

I have been weight training for a year and I was fully ready to lose some muscle as a consequence of this experience. Guess what happened? i continued gaining muscle, but not as quickly. I had a lot of ‘off’ days when my energy was low. I had a couple days where i backslid.. and i also had a few days where i had breakthroughs. So basically, lifting weights while fasted had pretty similar results as not being fasted.


I do not believe in silly things like ‘anabolic windows’ and ‘protein timing’. Bayesian bodybuilding has spent a lot of time busting myths like those, so check that site out.

However, I am not a serious bodybuilder. I go to the gym, push some heavy things for an hour 5 days a week, and have never had a personal trainer or read a book on the topic. But I still built muscle on a caloric deficit while ignoring all nutrient timing rules on a diet that is maybe 2-5% carbohydrates at most. If i can build muscle while breaking 100% of common dietary advice, you can too. If you have weight to lose, you can lose it very quickly with intermittent fasting, so the time you will lose out on potential muscle gains will be short. I wouldn’t worry about it.


.. and low carb body building hero, Luis Villasenor, pictured above doesn’t worry about it either.

In summary..

In my experience, Ketogenic intermittent fasting is like ketogenic dieting with cheat codes on. I was able to throw the towel in and go back to ‘lazy keto’ in an amazingly short period of time. It took me a year and a half doing regular keto to lose 80lbs. But i lost 27lbs in 3.5 months. That’s almost twice the weight loss per month. To say i’m impressed is an understatement. I’d recommend it to anyone looking to shed some pounds.

If this article was of any help to you, please drop me a note. My email address is tucked away in the top left corner of this site. As always, thanks for reading! – David