I've heard this works all over the place. Like wife shaming. Dinner isn't to your liking? Berate her in public, embarrass her in front of neighbors, heck, slap her around a bit. Husband isn't doing his part in the bedroom? Fix that with husband shaming. Talk about it with your coworkers, tell his friends, post about it on the internet, have other women look at him with pity. I am sure that will fix things no problem. 
Yeah, being an asshole to people seldom fixes the issue. I have yet to meet a fat person that didn't know they were fat. Some just don't care and that is more power to them. Some do and are trying to fix it. Calling them a landwhale probably wont help. Like magnolia said, many heavier folks eat emotionally, berate them and they will just eat more. (source...ben and jerry's tastes great when you are pissed off).
"Corn syrup is everywhere; check your pockets."
"Stop this brownie talk, you devils!" - Sabine