my kids are veg too. it takes a lot of doing sometimes, and other parents get a little mad when you refer to their childen's lunch as what it really is. Hot dogs are not as fun as they sound kiddos, they are actually ground up intestine & 5% flies.
The only thing i can do is hope hope hope my kids make the choice for a kinder evolution, respect their choices when they make them.
My son decided at 4 to try chicken, and he said he liked the taste. However, a few hours later his little conscience began weighing on him, I think, and he decided to never do THAT again! (with me being very neutral & reflective). He was sick to his stomach.
My dd is 3 so we'll see.