As fun as fat shaming is, and I'm pretty sure you're joking anyway, this wouldn't necessarily be the best way to go. Children respond better to positive reinforcement than punishment. In other words, it's better to say, "Wow, I'm proud of you, you ate all your veggies!" than "Stop eating Goldfish, you're already getting fat!". We don't want to set the kid up for an eating disorder! (Though, I suppose one could argue she's on her way to developing one already...)