Over on the EXRX forums, there is a long but interesting argument going on about counting calories. More precisely, "calories in" versus "calories out" and its relevance to weight loss and its effectiveness. The CI/CO idea is that a calorie is just a calorie. If you take in 2000 and burn 2200, you'll lose weight. Take in 2200 and burn 2000, you'll gain weight. Only once calorie totals are in the right position does actual makeup of those calories matter.
For a long time, a comparison has been brewing in my head - CI/CO or total energy balance vs. exercise volume. Volume being sets x reps x weight summed up for a whole workout. Squats for 5 sets of 5 reps for 225 has a volume of 5625 pounds, for example.
Rather than reiterate my whole comparison here, I'll just link to my post. The whole thread is worth the read.
For me, the take-home idea is this: in strength training, we don't worry about the total amount of exercise, and then worry about the composition of that total. We start with "you should squat, deadlift, press, and do pullups" and then decide on sets, reps, and weights that will get us to our goal. If the total volume is too high (it'll wear you down faster than you recover), we cut it back - maybe less reps per set, or less sets, possibly even dial down the weights a bit. Not surprisingly, this is the opposite approach of most exercise recommendations you'll find in the mass media - "5 days a week, 20 minutes a day" tells you the total time, not the composition, of the workout.
In your diet, you could (I think should) do the same. Total calories is really only important once you've started eating healthy foods. You could start by cutting down to an optimal amount of food and then go swapping out the bad with the good. But you'll do far better if you change to healthy foods, and then worry about how much of it you eat. Heck, the second approach is also easier...