Another reason to stay as far away from family as possible

Irish grandmothers must have a club where they go and make up the cruelest ways to call their grandkids fat.

Two wrongs don't make a right. Just because the grandmother was rude to OP doesn't mean OP needs to be rude back. OP, tell your grandmother that what she said was hurtful and rude. If your grandmother reacts badly, you will at least feel good knowing you tried to handle it like an adult and you can move on with your life being aware that your grandmother is not a very nice person. If she apologizes, you would've saved the relationship and maybe she will feel so bad about the way she treated you that she will write you down as sole heir of her property after she dies. Try to work it out with her.

Your father is pathetic to be using grandma's intoxication as an excuse to act like a bitch towards you despite not knowing she faked it. I'm sorry but if you can't drink & handle your alcohol responsibly where it becomes acceptable to be a "rude asshole shit disturber drunk" then you shouldn't be drinking period. If your grandma is this much of a cow to you sober, I would hate to read what she actually is like to you drunk OP.

Not trying to be a jerk but here's an idea... lose some weight? These kinds of things wouldn't happen to you if you weren't fat. Use it as motivation, try to prove your grandmother wrong! Show her that you can get in shape! So sorry but YDI.

Fake being drunk next time too and say some stuff then snap out of it for dad. Two can play at that game.

Yo granny must hate you :P

It's a possibility she was and your being paranoid, sorry to say but drunk old people do seem to particularly good at winding people up

Hmmm, maybe you should get 'drunk' and tell your grandma some home truths, then tell her to chill out when she complains.