There are various schools of thought on this. For me when I was actively losing, I was very much learning on-the-fly, at first just focusing more on reducing the carbs as much as I felt I could sustain. But it wasn't until 2-3 months into the journey that I had finally completely let go of the old low fat mentality as well. Not that I was ever getting stuck into full-on fat bombs or anything, just no longer being afraid of natural fats as they came supplied with natural foods, like going with full-fat dairy, keeping all the fat on the meat etc.

If I had to do it all over again knowing what I know now, I guess I would have flicked that mental switch with regard to fat a bit sooner. After all, when we say we want to lose weight, what we mean is we want to lose fat. To my mind, that requires "training" the body to recognise what it already has by feeding on fat to satiety, while at the same time not allowing insulin via carbs to block that process, as well as getting enough protein along the way too.

I guess in summary, I would focus primarily - but not exclusively - on fat at first, until I'm clearly in fat burning mode (that goes beyond just achieving ketosis), then dial back the fat that I'm eating slightly in favour of protein, to further encourage the body to use the fat that it already has on board, now that it can recognise and access it without insulin getting in the way.