As I understand it, one of the largest factors in low carb dieting is that carbs are less satiating per calorie than fats and proteins. Also that simple/highly processed carbs are even less satiating, largely because they lack any fiber. So if you aren't counting calories, you're much more likely to eat less on a low carb and high fiber diet.

Regardless of what you do, counting calories will probably be the most effective method for losing weight. And even then, calorie estimations are rough, change based on how the foods are prepared, and highly dependent on biological factors unique to each person.

I'm working on Eat This Much (http://www.eatthismuch.com/) as a way to automate my own diet. It still needs some work to get to the point where I'm never thinking about what to eat, but I've been using it to gain weight very successfully over the past few months. Gaining weight can be a lot simpler than losing it, but it still helps to pay attention to what you eat to avoid putting on fat as opposed to muscle.

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