Check out fitday.com. It's free. You can plug in your current weight and height and it will spit out ballpark how many calories you need to eat in order to maintain current weight. Then you can subtract your 400-500 calories or whatever, to arrive at a good caloric intake for weight loss, respecting your size. As we lose weight, we lower it constantly.

Many who do low-carb healthy fat do not concern with calories at all and that's fine. Our muscles are sitting patiently underneath our layer of fat. As we lose weight, they begin to appear. I like to build mine a bit since this boosts even more fat burning.

In terms of exercise, it's really only serious body builders who need to eat way more. But I eat a bit more when I do weight lifting or anything anaerobic like HIIT.