Ketone meter changed the way I think about refeeding SW 83 kg CW 76 kw

TL;DR: one day refeeding with 3000-6000 kcal with sometimes half of that coming from sugar doesn’t undo the benefits of fasting for me.

I did OMAD with keto 3 years ago for 3-4 months with weight training. I lost ~10 kg (from 82 kg to 72 kg), but I also gained muscle (or at least strength). I worried a lot about my carb intake and would limit my vegetable intake. Somewhen 2 months in I started getting mucle twitches and no electrolytes helped. I even ended up in ER after I collapsed/fainted 3 times in a row (after which I continued keto for 1 more month, but then discontinued). Most likely, the collapse was due to getting up from hot bath too fast and running outside and then getting a rush of adrenaline as it was the first time in my life fainting. ER blood tests were all good for all electrolytes and other possible issues except for glucose, which they found at 3.1 almost 10 hours after fainting. To this day I don’t know why my blood glucose dropped so low. Maybe something happened within my liver and it couldn’t provide enough ketones or glucose.

I did a few 2-7 day fasts since then, but nothing interesting.

This year I started doing fasting again, as I gained the weight back (SW 83 kg) and my friend was trying keto for the first time and he motivated me to do some fasting again. I’m only a month in and CW is 76 kg. I occasionally do weight training, but my lifestyle limits that (mostly sedentary and a lot of stress from work).

My friend also immediately bought a blood ketone meter, which I later bought as well, cause I was curious and didn’t want my glucose to hit extremely low levels.

I measure my glucose and blood ketones daily, at least twice (I wouldn’t do it so often, but I bought a bit too many testing strips and I would rather use them up sooner than I stop doing fasting and lose interest in measuring things). It has never dropped below 3.5 and even then just for short periods of time.

My current plan that I’m doing is at least 48 hour fasts and then one day of refeeding (3000 kcal) on anything I want. I try to eat healthily, eating as much as possible vegetables and protein-heavy foods. This is essentially 60-hour fasts with about 12 hours of refeeding.

My cravings for junk food have dropped significantly after the first two weeks, but I still occasionally eat a chocolate bar or go out with friends and eat/drink a ton of food.

What has surprised me the most is that there were at least two refeeding days where I ate around 1500 kcal in chocolate. My blood glucose would be 8 mmol/L in the evening. The next day my glucose would be 5-7 mmol/L, while ketones would be around 1.0 mmol/L. I’m genuinely surprised that I can get into ketosis in less than 24 hours, even if I eat a freaking large chocolate bar (200 g). I definitely don’t recommend eating that much sugar (cause it probably still causes inflammation), but it’s genuinely mind-blowing to me that you don’t undo all the benefits with refeeding and can be back on track the next day.

And I don’t even feel any more hungry on the first day of fasting than I would on the second (that’s a month in, to be fair).

What also surprised me is that my gut feels a lot better than during or after prolonged (3-7 day) fasts. I am never constipated, nor bloated.

I also don’t take any electrolytes nowadays, cause they used to upset my stomach on the 3-7 day fasts that I did (I was probably just doing too much of those).

Just wanted to share this, because back 3 years ago when I was doing keto and OMAD, I was dead sure that if I ate a freaking tomato, it would kick me out of ketosis for 3 days and those 3 days would be hard. I would have probably lasted for much longer, if I allowed myself occasional refeeding. Even now, I was initially worried that the 1-day refeeding may be making things harder, but it’s not. YMMV though and still a long way to go for me to my GW of 70 kg (my goal to be specific, is to weight less than 70 kg after a week of refeeding).

My now current plan is to go 2 days fasting, 1 day refeeding for as long as my results are within projected 0.1 kg/day lost (tracking those in a spreadsheet). And if that slows down, I may do something completely unexpected to my body - refeed for 2 weeks and start again. Not increase days of fasting, cause that would probably mean even bigger losses in micronutrients and muscle mass.