Well I make him walk on the mornings he doesn't want to. Dragging kicking and screaming if necessary (but it that has never lasted more than about a minute). Don't engage, don't give any options. Just say today we are walking to school and head out the door. If he continues kicking and screaming I would take away something he wants or possibly say that if he doesn't stop immediately then there will no park after school or straight to his room when we get home. Don't engage - there is no power struggle over things that matter in our house, he will do as he is told.
As for food, we follow the "You will eat it or you will go hungry" method of eating. It isn't as harsh as it sounds as I do try to ensure that we all get something we like at each meal.
If he doesn't eat what he is given then he doesn't eat - not my problem. My job is to provide him with good nutritious food, it is up to him whether he eats it or not.
I am perfectly willing to admit that we run quite a strict household, but to be honest my son is quite clever enough to see what behaviour is acceptable and what is not - and use his good behaviour to his advantage when he wants something! I can be a total sucker for a good little boy who gives mummy kisses!