@Swiggy
Can i ask how many g of carbs a day you were eating, on your lchf? Including all the virtually invisible ones that we often forget to include (i have fallen into this trap too often to count!).
Voleck and Phinney talk about how variable our personal reactions to low carbing can be. One person may get the full benefits of it on 80g carbs a day, while another might need to be under 20g a day for ever.
In my case, i had to work out where my personal carb tolerance lay (and sadly, that was under 20g a day) in order to see the blood glucose levels I wanted. This is just speculation, but if you were low carbing and high fatting and gaining weight, then it sounds like you were in a vicious circle of too high carb (causing insulin resistance) and too high fat. Insulin is the fat storing hormone, so we can only eat raised fat
and not gain weight if our insulin levels drop
enough - and that means dropping the carbs
enough. And for some that is exceedingly low carb.
I know that it was a depressing day when i first realised that for me, my low enough was well under 20 g, and that if i stray over 40g carbs and have even normal fat for more than a day or two, the weight piles on.