On the one hand, I want to teach them good eating habits. On the other hand "experts" say that you shouldn't make mealtime a battle because the kids get an inflated idea of the importance of food and its place in power struggles, leading to eventual eating disorders. For pop psyche, that actually sounds like a pretty reasonable concern.
In your peas/mac-and-cheese example, he's learning that vegetables are a punishment. It took me years to recover from this conditioning and discover I actually like the damn things.