#Weekly experiments / Healthy

Week 16: Intermittent fasting experiment

This post is long overdue, but it ended up being longer than I intended. Week 16 was dedicated to intermittent fasting, which is a regular practice for several Titans in the book – including expert on ketosis Dominic D’Agostino, doctor and self-experimenter Peter Attia and iceman Wim Hof.

Intermittent fasting

  • What is intermittent fasting?
  • Why is so popular?
  • How to do it (popular IF protocols)
  • Is IF difficult? Can you have your fatty coffee and count it as fasting?
  • My experimental protocol and experience
  • Conclusion

What is intermittent fasting?        

Term “intermittent fasting” is used to describe various protocols where periods of feeding are alternated by fasting periods. In simple terms, instead of the constant eating (remember the “5 small portions per day?” advice?) you would do shorter fasts in more-or-less regular intervals.

Why is IF getting so popular?

Host of reasons. I wrote about fasting before, and most of the benefits apply to intermittent fasting too. Our bodies evolved under a reasonable balance of anabolic and catabolic processes. I’m not really qualified to get nerdy here, but beautiful explanation of this was given in Tim’s  Life Extension Pilgrimage podcast, by a little girl who said when asked about metabolism “isn’t that when you grow things or you break down food?”. Clearly, we need both.

What are the real reasons why people would fast?

Weight loss and lowering the body fat are important for some.

Cost saving sounds interesting too, but in general I’d say that the saved money goes to buying higher quality food for your eating windows. There’s definitely big time savings – by not planning, preparing and eating some of the meals.

But it gets really interesting when you start looking at health benefits. Improving insulin sensitivity and reducing blood glucose are related to a plethora of diseases, as well as inflammation, oxidative stress, . There are studies suggesting that intermittent fasting (as one form of caloric restriction) has positive effects helping to prevent or manage better CVD, diabetes, Alzheimer’s, Parkinson’s and cancer. And let’s face it, these are the mass killers and all of us are at threat.

With all this, no wonder regular fasting in one way or the other is connected to longevity, and not only when caloric restriction happens.

How to do intermittent fasting

There are different approaches to intermittent fasting with different levels of difficulty. One of the most popular ones is 16/8, where first number depicts number of hours you fast (16 hours without food), and the second defines the feeding window (8 hours with food).

Does 16 hour without food sound scary to you?

Don’t worry, you can “cheat” by including your sleep hours. For example if you want to follow 16/8, your eating window could be noon – 8pm. Good news for people who skip breakfast – they already do intermittent fasting.

You can also try 18/6 protocol or even shorter eating window (longer eating periods are recommended for women).

Another popular option 5:2 (normal eating for 5 days followed by 2 day fast), or eat:stop:eat (24hour fast once or twice a week), or if you feel bold and adventurous you can try fasting on alternate days (only eat every other day).

There’s also Warrior Diet protocol (4 hour feeding window, 20 hour semi-fasting with some amount of calories allowed), but I personally don’t like it because it includes (over)eating at night. From both scientific and anecdotal evidence it doesn’t seem like a good idea, I think would just result in messing up my circadian rhythm and poor sleep.

Pretty much any IF protocol expects that you will not overeat during feeding windows, and that you will eat fairly healthy food – predominantly veggies, meat/fish and healthy fats.

But through Dr. Rhonda Patrick I came across interesting research done by. Dr. Sachin Panda with mice, and even more interesting research by his colleague Ruth Patterson with breast cancer patients. Their protocol is called “time-restricted eating” to make it less scary (who likes “fasting”?). Their studies achieved great results even with 12h:12h (or even better with 9h:15h) ratio of eating and fasting, all of it with a “normal” diet.

More info about intermittent fasting

Note: Please be cautious if you want to try it. Listen to your body, read more, and consult your doctor/nutritionist if you have concerns.. Also note that women tend to fare better with easier protocols (longer feeding windows). Don’t overdo it and be careful. Please.

Is it difficult?

It might be at the beginning, especially if you’re not fat adapted yet.

But IF quickly works its magic with ghrelin and leptin levels (hunger and satiety hormones), so it gets much easier over time. For example I regularly skip Monday breakfast and lunch, and usually don’t feel any discomfort.

Does having bulletproof coffee count as fasting?

I have to say “no”. To really fast, you have to skip the butter for sure. MCTs probably too. There’s a reason why some of the high fat diets are dubbed “fasting *mimicking* diet”.

I could hypothesize that maybe we could close one eye and say that having just C8 still counts as fasting, because it doesn’t go through standard metabolism, but frankly I have no idea about that. So if you want to do this, skip your morning BPC. It may not kick you out of ketosis, but it will start your digestion.

My protocol for experiment

I decided to go with 16/8 protocol (16 hours fasting, 8 hour feeding).

That meant that I was

  • Skipping breakfast completely. Not even fatty coffee, only black coffee or some tea
  • Lunch shortly after noon
  • Early dinner finished before 8pm.

I stopped any other dietary adjustments that I am normally doing – no 24 hour fast on Monday, no bulletproof coffee or MCTs for breakfast, no low carb or ketogenic days.

I was still trying to eat healthy-ish, I was avoiding gluten and other things I’m allergic to, as well as outright crappy foods. At least that was the plan – it didn’t go as well as I was hoping to.

My intermittent fasting experience

I thought it’s going to be a breeze because I’m already used to fasting and have no trouble with it. But after a few days of IF I came to think that for me the “high fat low carb” component is probably the key to making fasting easy.

Monday was fine, I had a big lunch with group of ex-colleagues from my previous company. We went for dim sum, so my lunch had unusually high carbs. Then I had salad and fish for dinner, but after that I had strong craving for sweets (!).I told myself “discipline is freedom” (thanks for that, Mr. Willink) and managed not to eat anything after 8pm.

The next morning I had both tea and coffee, but I could feel the hunger coming and couldn’t wait for lunch. I had big set meal at a sushi place. Luckily that evening I went for an event without any food, so I just had early healthy dinner on the way and went to the event. It dragged until 10 so I again dodged the sin of late eating.

But since then every afternoon and evening felt like a torture. I was distracted by the feeling that I need to eat, now. Ideally something sweet. Local branch of Starbucks must have been really happy with sudden increase of snowskin mooncake sales volumes (my excuse being “they will stop selling mooncakes soon so I should enjoy them while I can”).

I really wish I could measure my leptin and ghrelin during that week, it must’ve been quite a rollercoaster.

It was bad, I forgot how big impact these things have on my mind and productivity.

On Saturday I gave up the experiment and had a nice protein rich breakfast (scrambled eggs, sardines and veggies), which finally kept the hunger and cravings at bay.


So is intermittent fasting bad? The 16/8 protocol didn’t work very well for me, but that doesn’t mean it won’t work for you.

I’m not here to blame IF for how I felt. To be fair, I made a few mistakes on the way. Eating lots of carbs would cause problems even without IF. Plus doing IF during period when my hormones are off anyway was probably not the best idea.

So please don’t discard it, try. Intermittent fasting has potentially huge benefits (read again the chapter “Why is IF getting so popular?”). It helps body to switch between glucose and fat metabolism, allows it to clean and rebuild, potentially lowers calorie intake, etc etc.

Intermittent fasting could help you to look great, be healthier and live longer.

So give it a try. I just know that my current approach (BP coffee in the morning, and 1 day fast every week) makes it much easier for me to keep all the other restrictions that I (or my allergies) give myself, including staving off the carbs’n’sweets cravings.

The best thing to do is to test a few approaches and find the one that is the most comfortable for you.

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