I remember something my father used to tell me, before I lost 10 kg in 6 months and was still overweight:
My father: "Sonia, back when I was obese, people used to really bully me about it, until one day, I finally said to them "I can lose fat, but stupid is forever." They never bothered me again since. Whenever someone bullies you like that, say what I said, ok?"
Man, I love my dad so much.