I agree with LT about habit forming and focusing on where you want the meal to be. For me meals times are very special times in the day for us to connect, eating on the run (for adults as well as kids) is not something I think benefits us.
I would pack the crudites for out and about snacks, in the stroller if really necessary, I always set DS up somewhere for his snack if we are out, even a park bench at the play park, he sits and eats his snack and once he is finished he goes to play again, and knows that he may not run back and forth to get more food.
My DS has also always loved fruit. A couple of times I have cut right back on the fruit I give to ensure he took a balanced diet. The first day I got a few shouts, cries and temper tantrum. I cuddled him through it, said I understood he wanted fruit, said it was my job to ensure he is healthy and offered something else (I wasn't mean, I didn't offer broccoli which I know he hates, I offered a veg or bread stick or something I know he doesn't detest). By day 3 he was back on a much more balanced diet. I would never withhold fruit for punishment but I will for health reasons. Hope that makes sense.