Be that as it may, he's still YOUR kid and YOU get to call the food shots. And I get that she doesn't want to pay too much for meat, say, but if you sent something and let her be the bad guy, so she got to say "Sure, you can have some mac'n'cheese, as soon as you eat 3 bites of meat!" that's also not asking a whole lot. Just because it isn't "junk" ie candy or cakes or ice cream all day doesn't mean it's nutrient-dense food or "good for him" either.
But if you could work a compromise where he gets only so much pasta, or so much AFTER what you send (like the yogurt or supplements he won't take in the mornings, maybe?), or none past a certain time of day (carrot sticks only after 1PM or something like that), might that work?