a case of calories in versus calories out or is there more to it?"
I'm going to commit nutritional blasphemy here and tell you that calories in vs. calories out is only a small and, relatively, unimportant part of the nutritional equation when it comes to fat loss.
In fact, I don't have ANY of the clients in my company count their calories yet they still manage to burn fat faster than most people.
You see, it's not the calories that truly matter in a diet. If they did, then I could eat 3000 calories a day of dougnuts and expect similar results to 3000 a day of lean chicken breast or even neat Vodka and, clearly, that's not the case at all.
In fact, what is much more important is the nutrient density of the foods we eat and the effect of those nutrients upon our own biochemistry (again, 3000 calories of vodka are going to do very different things to your body than 3000 calories of chicken and green veg aren't they?).
Now, for the naysayers out there who've used points-based diets that allow you 200 calories of chocolate if you wish and still lost weight, let me just clarify what's going on here...
Yes, you may well lose weight as the calorines in/out model has been shown to have a stronger correlation to WEIGHT loss but you're probably not losing much FAT. In fact, you're probably canibalising the most precious metabolic resource you have... muscle!
Calorie control for weight loss? Maybe (Though I personally think not)
Calorie control for fat loss? Hell no!
The best fat loss programs are really simple.
Eat 'clean', train regularly and with as much intensity as you can tolerate, drink lots of water, get to bed by 10.