People would describe it in different ways, and see different reasons for it, but I am pretty sure that anyone with an extended history of anorexia will tell you that starving is kind of like a drug. One doesn't want to dwell on that because, well, incredibly unhealthy to describe a potentially fatal condition in positive ways. But it's part of the condition, and the idea that there's a genetic quirk which accounts for that makes some sense to me.