It has to be done on a large scale though.  Japan has their entire society fst shaming, which is why it works.  In the U.S., unfortunately, for every fat shaming shitlord there are 10 other fatties or enablers just waiting to coddle fatty fee fees.  So when you have one person saying you're disgusting and ten saying you're beautiful and deserve more ice cream, it's pretty obvious who they will listen to.