Personally, I don't think any form of shame works. It may 'work' short term, in that you avoid a second helping when in company with others. But once alone at home, with access to food some of us will pile into the crisps, chocolate or cheese, or whatever lights our fire - and more than make up for what we didn't eat in company of others.
I believe in a positive model, much like child care, of praising the good.
I've been trying to do this for years but I think I am getting somewhere. I have actually had some counselling for an eating disorder.
And it is something I need to take ownership of.
So things like setting achievable goals, finding good examples, and not making people feel ashamed of who they are. But rather to take responsibility, if I eat this big old fattening dessert I need to factor in less food, or less fatty foot, in the rest of my day. I'm not bad for wanting cake or whatever but I can't just have cake and fatty foods all the time and expect to be healthy.
This needs to be taught in schools much better.
I also think that fatty food should be taxed like cigarettes and alcohol. Exactly how we define fatty foods could be tough, there will be some grey areas but there are lots of things that are clearly unhealthy and calorific like processed meats, pies, desserts, some ready meals, chocolate bars, crisps and many other 'snack foods'.