After being on-and-off low-carb for almost two years now (!) I am convinced that calories absolutely matter.
There are many benefits to low-carb eating besides weight loss. Maybe people will testify to acid-reflux cures, better sleeping, control over blood sugar, ec. I can!
But JUST low-carbing alone doesn't seem to work beyond a certain point.
I think what happens is that low-carbing helps get your hunger under control so you are naturally eating less calories than before. However, for most very overweight people this isn't enough to actually bring you all the way to goal - just down to a lowever stable level than you were at before.
That in itself is a good thing, of course. I'm not knocking it.
But I think a certain amount of calorie consciousness is needed also to really achieve goal.
For example, I had to stop eating macadamia nuts. There are just way way too many calories in them, and I suspect more carbs than we are led to believe. A single 50 gm bag of macadamias every day can, by itself, make the difference between losing 30 lb over the course of year or not!
Similarly, I try to subsitute chicken, fish or even lean pork roast for fatty red meats. They are better calorie bargains. And I try to put a break on oils, butters and mayo - they all have 100 calories per tablespoon, which can't be ignored. So I used them conservatively.
Low-carbing helps - but you can't violate conservation of energy!
doug