Calories not important. Type of calories important. Fibre contains calories, but they are locked up in a hard chemical shell that your body cannot crack, and therefore is unaffected by it. So, 200 calories of regular carbs are far more fattening than 200 calories of fibre carbs.

Edit: When I said that the body is unaffected by it, I was referring to the fact that fibre does no trigger the same cascading chemical reaction that other carbs do. No amount of fibre will cause an insulin spike and increased fat storage.

The types of foods (and NNSs) we consume, and the chemical affects they have, are more important than the amount we consume.