I'm on low carb/high fat and don't count calories. That said, I don't eat a lot at a time...a tablespoon of peanut butter or a couple of pieces of cheese or even a big handful of pork skins (they give me my crunch fix). I also add a little coconut oil to my coffee.
This is all out the window if you eat carbs. Having the high fat and knowing this is a motivation for me. If I've already had coconut oil in my morning coffee I won't risk the carbs later on.
This way of eating isn't for everyone but I have Diabetes and it's the only way I can eat and lose weight.