A 3,150 kcals Meal + 34 Hours of Fasting. What’s it Like…

A 3,150 kcals Meal + 34 Hours of Fasting. What's it Like... - The Bronx


Location: The Bronx, NYC.

It’s 5:30 A.M. on a cloudy Monday morning. In a couple of hours I will be flying over the Atlantic, in a trip back to Romania, my beloved home country. It’s going to be a 24+ hours adventure…

Last night I had this crazy idea of doing a feast before leaving. Then, I would fast all throughout the trip.

Fasting during traveling is nothing new to me. I’ve been doing it when I flew to Thailand and also to the U.S. from Europe. I’m doing it almost always when I’m flying. 24+ hours should be easy since some of my fasts lasted for more than 40 hours.

But wait, a feast? How much food in a single meal would it take to kick me out of ketosis? Yes, I’m still following a well formulated ketogenic diet.

The Nitty-Gritty

I didn’t think too much of the details. I was more concerned about my next 24 hours, with all the uncomfortable switching/transferring between subways, airports, busses until I would get home eventually. I wasn’t looking forward to it.

On top of that, last night’s sleep wasn’t in my top 3.

However, the thought of eating so much got me a bit excited, especially because I was consuming the foodstuff I enjoy most and, notably, because I usually under-consume calories.

First, I tested for ketones. I was at ~1 mmol/dL. I still use the urine sticks because after ~2 years of mostly constant ketosis, they still work for me.

Then, I did some calisthenics for ~20 minutes:

150 – 200 pushups,
20-30 chinups,
playing with some 30 pounds dumbells,

Followed by a 5-10 minute cold shower.

And then, food:

350g (~12 oz) mixed nuts and seeds (peanuts – yes!, cashews, almonds, walnuts, brazil nuts, sunflower seeds)
100g (3.5 oz) full-fat Greek yoghurt – I had thrown-in some of the mixed nuts from above.
30g (1.05 ounce) cheese
300g (10.6 oz) salad (200g of broccoli + cabbage, 60g turkey bacon, 40g full-fat Greek yoghurt)
100g (3.5 oz) dark chocolate 90%.

It was indeed a feast. I felt full, but I didn’t feel stuffed (like I couldn’t breathe).

It took me more than an hour to eat everything. However, I felt super-satisfied. It should have kicked me out of ketosis, but did it? I wouldn’t have cared if it did…

Putting everything together in my Cronometer, this clocks somewhere at:

~3,150 kcals
~80g of total carbs: – 54g net carbs, 26g fiber
~260g of fat
~110g of protein

Shortly after finishing up, I went to a nearby Starbucks to get some work done before the trip. While there, I had 2 double espressos with a substantial amount of whole milk.

At 10 A.M. I got back home (in the Bronx) to get on with the packing and with sorting the last details of my upcoming trip.

I checked ketones once again. It was 2 hours and a half since I ate. Ketones were moderate to high (about 3-4 mmol/L). I didn’t see that coming…but I was pleasantly surprised.

I suspect my sensitivity to insulin has improved much since I started my protocol in late September 2013.

I didn’t have too much time to ponder upon that. I felt super-energetic, possibly because of the food intake + too much caffeine.

I fooled around with the dumbells for a while and then I took another 10-minute cold shower…Then I left…

Flash-forward 34+ hours…

I hadn’t eaten anything since my feast. I didn’t have the slight feeling of hunger. All I had during my trip was purified cold water, some coffee, and some nice red dry wine (during my flight).

Now, it was past midnight the next day… I was at home, safe, sound, and not tired at all.

I checked ketosis. The sticks were dark pink. For validation, I felt it (ketosis) in the fruity breath as well.

I decided to break the fast during night time just for the sake of it. I usually don’t eat when it’s dark, but due to my current physical conditioning I could break the rules every now and then (even more often than I currently do).

So I broke the fast the same way I started it:

150g (5.3 oz) mixed nuts
100g (3.5 oz) dark chocolate 85%
20g cheese (0.7 ounce)

I didn’t have jetlag and I didn’t have trouble sleeping. I slept for about 6 hours and then headed straight to gym to do some weightlifting.

My focus over the next days would be to recover from the trip. Even though I don’t feel tired, I believe my body needs appropriate time to rest (sleep at least 7 hours per night)…


Folks reading this should not think I somehow advice people to do what I do. Nor that I claim that what I do is optimal and should be a general approach for everyone.

I usually consume a well-formulated nutrient-rich-low-calorie-ketogenic-diet, loaded with vegetables, greens, and plant foods, and moderate-to-low in protein (less than 1g/kg). I do intermittent fasting almost everyday, with an 18+ hours fasting window and a 6 hour feeding window in which I eat twice. I often do 24+ hours fasts and sometimes 48+ hours fast. So, I think I have a lot of room to experiment with overfeeding.

I don’t eat at night and I try to live my life in synchronicity with my circadian clock. I use cold thermogenesis everyday (ice bath + cold showers) and sometimes I break sweats in the gym and take hot showers to animate my strategy. Overall, it seems to be working well so far…

Here’s a photo that I took in Miami about a week ago:

A 3,150 kcals Meal + 34 Hours of Fasting. What's it Like... - Miami

I did this post mostly by popular demand from some FB friends. If there’s something that I can help you with based on what I wrote here, please share your thoughts in either of the comment sections below.

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12 Responses to A 3,150 kcals Meal + 34 Hours of Fasting. What’s it Like…

  1. Richard Carlsen says:


    Once again, you have provided us with some very interesting observations that is providing food for thought. I appreciate your not only thinking outside of the box but outside of the circle. All too often I see folks get so locked in to one formula and fearful of making any adjustments that they miss the big picture with all of the benefits of ketogenic nutrition.

    Again thank you very much



  2. Dan says:

    Interesting stuff. Thanks for sharing.

  3. Laura says:

    Salut Cristi,

    I am following you for quite some time and here’s a good time to say thank you for the insights! Though sometimes they prove a bit too scientific to me at the first read (I have read your 2 books “Ketone Power” and “Periodic Fasting”), I use them as a reference to which I come back to whenever I am looking for some scientific background to something I have been doing :). Now, I am on IF since March this year, but I do not measure my macros- I just eat what I want as long as it is high fat/low carb. Sometimes I also do 48 hrs fasting without the smallest headache too. Ah, yes and I have lost 10kg since then- which I could never do in my entire life with any other way of eating.
    I was just wondering if there is another way of knowing I am in ketosis than measuring the ketones like you do. I hope you can see, I am a bit more freestyling here, and I don’t want to go all scientific with keto sticks and stuff, so do you have another method to know you are in ketosis?

    Multumesc! ๐Ÿ™‚

    • Chris Chris says:

      Laura, the ketostix are super inexpensive. However, one way without measuring would be the ketone breath…which is sort of a “fruity” breath which people in ketosis often feel. Since acetone (ketone body) is mostly excreted through the lungs, that’s what gets the fruity (acetone) breath. But like I said, the least expensive would be with the stix. It’s not acurrate for everyone but it’s a good start. A pack of 50 ketostix would be ~$10.

      Thanks for your feedback on the books! If you still feel unsure, please keep replying and I will do my best to help.

      Cristi Vlad

  4. Michelle says:

    Thanks for all the great articles. I have been on strict keto since 11/18/14 and was at a calorie deficit at first but never really adapted. I do not really need to lose weight but would like to be more ripped. I upped my caloric intake at the end of april to 1700-2000 per day macros are always 80/15/5.
    I mainly started keto to improve health. Since I upped my fat I feel more adapted and have noticed some improvement with the adrenal/thyroid hormonal issues. I have heard you should not fast in the initial phases of keto adaptation or fast if you have adrenal issues. Do you know if this is correct and if so how will I know when it’s ok to start IF?

    • Chris Chris says:

      Michelle, thank you for your input!

      ” I have heard you should not fast in the initial phases of keto adaptation or fast if you have adrenal issues. Do you know if this is correct and if so how will I know when itโ€™s ok to start IF?”

      I don’t listen to people who make generalizations such as “you should not fast in the initial phases” so I’m not sure how much you value the advice you have been given. I usually focus on personal approaches…

      Unless I would see some value arguments of people doing ketosis and having adrenal issue I’m not sure how this could seem valid.

      Personally, I experimented with fasting almost ever since I started constant ketosis, though I did not fast on a regular basis. And I also did not feel the “adrenal issues”. I’m not sure how this can apply to others though…

      Hopefully this helps somehow.

      Cristi Vlad

  5. Anna Dandeker says:

    Hi Cristi,

    Thank you for all the info you’ve shared. I’ve read Ketone Power and Pereodic Fasting, and loved them. Can’t wait for your next book.
    I’ve been on strict keto since January 2015, and lost 15kg, the plan was to lose 13, so some extra fat fell off ๐Ÿ™‚ I do IF for 19 hours practically every day. But I do miss my wine ๐Ÿ™‚ In your blog you mention that you do fastings for over 48 hours but still drink red wine. Would that count as breaking the fast then as anything over 50 calories counts towards “eating” or do you think the wine calories don’t matter?



    • Chris Chris says:

      Anna, thank you for your comment. And congratulations on your success! ๐Ÿ™‚

      “In your blog you mention that you do fastings for over 48 hours but still drink red wine.”

      That happens every once in a while. Everything I do is mostly random (see Taleb’s Antifragile book) so please do not generalize. Even though I do IF almost everyday, I randomly (and very often) fast for more than 30+ hours (like I did above).

      “Would that count as breaking the fast then as anything over 50 calories counts towards โ€œeatingโ€ or do you think the wine calories donโ€™t matter?”

      To me personally, it doesnt count. For someone with a poorer health condition, requiring stricter rules for fasting, it may count more. So again, I cannot and will not generalize. Everything is context based.

      Since you read my books, can you please be kind and leave a short and honest amazon.com review? It may take less than 60 seconds and it may help others decide to read/not read the books

      Cristi Vlad

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