"A pound of muscle takes ~100 calories a day to survive"
This defies math when on the order of 1/3rd of your weight is muscle. The more commonly cited value is 50 calories a pound, and even that appears too high.
This article cites 6 calories per pound: http://www.thefactsaboutfitness.com/news/cals.htm
Building muscle, without changing your diet, will cause changes in your body that will reduce the impact of what you eat. A pound of muscle takes ~100 calories a day to survive, a pound of fat ~10. It also changes your body in other, more subtle ways.
Serious low-carb dieters (as opposed to people who just binge on meat instead of cake) often do weight-training. (Especially women!)
They eat 11-15 calories/lb of current body weight, with lots of protein, which sustains them healthily and creates a caloric deficit. (And the ketosis helps.)