I was really skinny as a child, all the way through high school, until I went on the pill. In those days, the hormone mix for the Pill was pretty crude, and I gained a lot of weight, which I fortunately lost when I went off of it. But before the pill, I was scrawny, although my appetite was normal. I even tried downing milkshakes with raw eggs to gain weight, but I was still stick thin.

Once I hit 30, my metabolism slowed down, but I still had no problem keeping the weight off when I put my mind...