It was after midnight. I was visiting my aunt and uncle and had wandered into the kitchen for something to eat. Always a night owl, my aunt sat at the kitchen table with me. She watched enviously as I chomped on a bagel smeared with cream cheese and piled with vegetables. “I wish I could eat like,” my aunt sighed. “Like what?” I mumbled, looking at her quizzically. I was in my early 20s and I ate when I was hungry, which was pretty much all the time. I worried a little about my weight, not wanting to get too plump, but besides that, I didn’t think much about food. I bicycled to school every day and was active enough and young enough that I could get away with stuffing my face with pretty much any kind of food at odd hours. My aunt, in contrast, had always been unhappy …