I'm a compact person (160cmtall, weighing 50kg on a heavy day) and I get through about 2000- 2500 calories a day. I don't count them and was surprised when I did, following another post like your own.
I live a low carb lifestyle and have done so since 2013. I'm also gluten-free, although that's only about the last 4 or 5 years.
To get my calories, I tend to concentrate on good nutritious food. I have full fat (rather than low fat) dairy - aside from yoghurt as curiously I prefer the low fat at breakfast time.
I have fattier cuts of meat. I don't mean slabs of whatever with a great layer of fat on the outside, just fattier cuts, like belly pork or lamb. It's amazing how it all adds up.
I love vegetables and eat plenty of them, but I make sure I'm not using those to fill myself up if I haven't had enough nutrition.
After a while it almost becomes second nature.