@FinallyHere
I just wanted to pick up on this comment:
I've been feeling virtuous at keeping low carb. and doing intermittent fasting, while serving myself ginormous portions of meat with a few veg
You're eating too much protein and not enough veg. Remember that our ratios are supposed to be fat:protein:carbs; that looks like you're doing protein:fat:carbs instead.
The reason you need to watch your protein is that it can also result in gluconeogenesis, which impedes weight loss. Read this, from healthline.com :
Protein is a very important macronutrient, which most people aren't getting enough of.
It can improve satiety and increase fat burning compared to other macronutrients (1).
Generally speaking, more protein should lead to weight loss and improved body composition.
However, low-carb dieters who eat a lot of lean animal foods can end up eating too much of it.
When you eat more protein than your body needs, some of the amino acids in the protein will be turned into glucose via a process called gluconeogenesis (2).
This can become a problem on very low-carb, ketogenic diets and prevent your body from going into full-blown ketosis.
According to Volek and Phinney, a "well-formulated" low-carb diet should be low-carb, high-fat and moderate protein.
A good range to aim for is 1.5 - 2.0 grams per kilogram of bodyweight, or 0.7 - 0.9 grams per pound.