It's about the Benjamin's, not the "nutritional value" of anything...
I made it thru 4 pages of posts and this may or may not have been covered, but wanted to throw this out there.
I don't believe the root of the "replacement meal" is even about the nutritional value of the lunch that the parent provided. Lets face it, most schools here in the US are struggling financially. The more students that eat a school lunch, the more $ the lunchroom receives from the state. If a parent sends lunch with the child, the lunchroom doesn't receive credit for them eating...
Like I said, it's all about the Benjamin's...