It looks like last year's weight-loss was not (just) caused by renouncing PUFAs. So the most likely cause now seems to be the ex150 diet itself.
So I am kind of torn between 'doing nothing and seeing what happens', waiting to see whether my weight ever stops rising, and 'trying ex150 again'.
In terms of working out what's going on, I think both would be interesting things to try. So I'm going to give the casting vote to vanity.
97.3 kilos (BMI 30.7, obese) is uncomfortably heavy and I'd like to get that down to something more reasonable.
The precipitous magical weight loss I saw last year happened after two short bouts of the original ex150ish last June, and noticeably didn't happen after the sour cream version, or after the heart-attack-keto experiment. The third ex150ish bout in September did seem to cause the usual spectacular weight loss while it was going on, but was immediately followed by a visit home and a really spectacular weight gain.
So I'm going to try to do the original ex150ish that I did last June again.
Here's the definition I wrote at the time:
https://theheartattackdiet.substack.com/p/ex150ish-definition
I'm going to try to stick to that definition as much as possible for a couple of weeks.
Predictions
I expect to go into ketosis, with attendant mild headaches, fairly quickly, and will take electrolytes (https://www.amazon.co.uk/gp/product/B07YN75QLS) for the first few days to try to reduce the effect of 'keto flu'.
I also expect to feel like I've got an endless supply of energy and mental clarity, but that that will somehow feel 'a bit thin' and run out quickly if I try to use it seriously.
Weight-wise, I expect that to cause roughly 1kg of water-weight loss quickly over the first week, which will come back on once I start eating carbs again.
I also expect to lose actual body mass at a bit more than 0.5kg/week while I do it.
So in two weeks I expect to be a bit below 95.3kg, at which point I'll come out of ketosis and go back up to 96.3.
I also expect to start overheating, and to have to reduce my thyroid dose somewhat.
I'm fairly confident of all these predictions and notice in advance that I will be surprised if any of these things doesn't happen.
The interesting bit will come after that:
If ex150ish really does carry on causing weight loss even after I stop doing it, then I'd expect my weight to continue to drop at about 0.5kg/week for at least a week after the water-weight rebound, before settling down and starting to rise again.
If not, then I'd just expect the water-weight rebound to be followed by slow weight gain at something like 1kg/month, at least until I get back to my current 97.3kg, and probably continuing after that..
It's been ages since I've done this! Wish me luck.
Godspeed!
Good luck!