Yes, I think this is why it is a difficult issue. There's a wide variation in kids, but people who see them often (like teachers) do know which ones are in trouble. I don't trust all teachers, of course. But who else sees the kids so often?
BTW, I'm past the age of feeding young children. I was always lazy about it, but the kids were always happy with the bowls of vegs in ice water (to keep them crispy) - carrots and celery, sure. But also cauliflower, broccoli, green beans, mushrooms. And bite sized fruits like apple slices, grapes, berries, pineapple chunks, etc. in a fruit bowl.
As long as they didn't need a plate or a utensil, they ate it. :-)
I agree with you on the teachers being able to pick the ones in trouble - or at least they should be.
My daughter is a little bit of nothing......but she is actually both taller and heavier than I was at her age. I'm not worried about her in the least. She'll be 8 in July, I was 13 before my height really started showing and my husband grew more than an inch AFTER he was OUT of high school.
As to the vegghie bowls, I only mentioned the celery and carrots because they can be had all year round and I don't bother growing them (too much work).
I keep junk food snacks around here, and won't deny them to my child or her friends when they ask for them, because more times than not they will raid the veggie bin in the fridge before they head for chips or cookies. There has been more than once that I reach into the bin to pull out stuff to make a salad and basically find a head of lettuce in there, the kids have eaten me out of all other fresh veggies :)
Tuesday my daughter and her friend are going to really learn just what it means to want somethings in the garden. They both want watermelons and pumpkins (neither really interest me) and so after they do their homework they will be out in the field getting rid of the weeds and preparing the area to plant those seeds on Thursday.
I've got 10,000 sqaure feet tilled up and can till up more - but these girls are going to learn that if they want it planted and harvested and it is not on my plans for my goals, they are going to have to deal with it themselves.
I'm a hard taskmaster - but I'm a lot better than the Nanny State so many wish to put these girls into. If nothing else, they will both learn self sufficiency at an early age.