Actually this threadrift bares no relevance to the OP, and it was my fault too...

As far as the original topic is concerned the only important thing is that school is the place that parents are expected to entrust their children for the best part of the day.

One meal of the day falls into this time period.

And as schools are *responsible for the welfare* of children for this period, whatever they provide during that time aught to be beneficial, including any on-site nutrition offered.