Not Pilot Gal,but my understanding is that everyone's body needs a certain level of calories per day - and of course that may vary from day to day according to activity. The advantage of low carb is that it takes you off of the blood glucose/insulin roller coaster that results in eating before you have used up all the fuel from your last meal - in other words you are eating for reasons other than true hunger. Once you eliminate that extra eating, you are back down to levels of food needed to fuel yourself, not to satisfy hunger brought on by low blood sugar. Less food and fewer calories without hunger allows weight loss.

What do you mean by totally skip the fat? It doesn't take much to keep you out of ketosis - >50 total carbs per day. There is still room for plenty of fat.