JohnP - I agree with the simple idea of calorie restriction, but I think there is much more to the puzzle, which includes satiety and hormones (particularly important for females).
For example, I was eating about 1500-1700 cal. half a year of the "normal" diet, was regularly jogging, but completely stopped losing around 75 kilos. Calorically that makes no sense. And if I went up in calories, I kept inching toward 80 kgs...... I felt like I had no control.
However, now I'm eating much more everyday 2000 - 2500 cal. (high fat/moderate protein/low carb), have stopped experiencing blood sugar swings, and am continually gaining lean body mass and losing fat. This also gave me the energy and confidence to take up heavy lifting. I'm now around 70 kg. and the scale keeps inching down, in a healthy, slow manner (I started eating low carb in January of 2012, then began nutritional ketosis as an experiment in November).
Anyway, I find I feel my absolute best mentally and physically on nutritional ketosis.
I agree that weight loss definitely has to do with calories - it is one side of the story - but its not the whole story.
Especially not for women.
Although I wish it were - I would have reached my goal weight a very long time ago if it were only about calories in-calories out.