(Sebastien Szczepaniak) #1

Hi Keto enthusiasts -

With my week 6 of a strict Keto Diet.
I am still wondering if full adaptation is done or on the way.
While I feel some signs of adaptation (mood, lack of hunger, etc…) I’d love to understand more about the physiology behind.
Am I right saying that true fat adaptation occurs when the big chunk of our tissues do not rely anymore on Ketones to run normally but instead do tap into breakdown of free fatty acids (FFA) quiet exclusively (except brain, blood cells…).
Is this the real adaptation? I assume this switch do not come overnight and I’ve read that it’s a process of 3/4 weeks to happen. But is this to “start happening” and then the “switching” process will go on during a couple of months ? or is this 3 weeks to completely shut off ketones utilisation and being fully fat adapted via FFA?
Thx much

(Jill F.) #2

Well I do not have a scientific answer per se, but I watched the show called Science of Fasting and another called Fat (I believe both were on Amazon Prime) and those helped me understand how your body uses fat as fuel.

For me I felt like the “switch” happened around 4 to 6 weeks into eating a ketogenic diet. I all of a sudden lost my cravings for sweets and carbs and went from being hungry all the time to eating lunch and dinner with ease. I started out on keto eating breakfast like eggs and bacon and lunch and dinner with a snack or two in the day to easily just eating 2x a day. Intermittent fasting just naturally started occurring. That is when I really started seeing weight and inches lost. I lost 40 pounds in about 5 months after this started.

Check those shows out the fasting one is fascinating to see the science behind how it works. For me I have done 18 hour fasts before but I just cant seem to get over the mental hump of I need to eat to extend my fasts out. I am going to keep trying!


Becoming fat adapted can take up to 6 months! I only began to feel a difference after more than 2 months. And then it was like a sputtering motor that was sometimes on and sometimes off. One morning I would wake up with no hunger and the next I would need those eggs and bacon in the morning. Some days I would feel tired and others I would have more energy. And as far as I have understood it, this is about using our glycogen reserves in the liver and muscles before we can become really fat adapted. Maybe this is different for everyone because I am 67 years old and dont go to the gym or work out. Maybe younger people turn into fat burners more quickly. I also ate dairy during the initiation phase and sometimes a keto dessert. Maybe this is why it took me longer. But I think people feel something is wrong with them if they don`t quickly become fat adapted in the shortest amount of time possible when they read this. I would think to become truly fat adapted even in the fastest person would take about 3 months. And this is when one can experiment with upping the carbs a bit too.At any rate- I am taking my time and enjoying this WOE. I slipped iinto IF 18/6 naturally and effortlessly. Similar to MommyJill I am too afraid to start any longer fasts at this time on my keto journey. That might change too - it is a bit like waiting to see what will happen next on keto.

(Sebastien Szczepaniak) #4

Thx for your answer.

It’s funny how one day I feel like “oh I’m on my way for fat adaptation” and the other day (like today), I feel angry and hungry, getting back to bad mood and feeling down overall.
I just need to be patient I believe… and keep Keto on!


Talk about weird. I had one day this week in which I ate nothing the whole day! I just was not hungry. I thought "Well if I dont want breakfast I can eat lunch later. " Then I had no need for lunch and thought I would have dinner, which I didn’t need either! Suddenly it was bedtime and i had not eaten all day.And I didnt feel sick or anything as it usually was when we lost our appetite in the past. I felt energetic. And then I got the bad side of being fat adapted- I was SO energetic that I could not sleep.
The next day I was back to eating Keto again. I will just let it unfold as it happens.