Re: Say something to the teacher or let it go...
I would email the teacher, but approach it as 'what can we do?' instead of any 'my son says that they lose 5mins every day for...'
Just explain that you're concerned because your son is coming home from school with half his lunch uneaten and he explains that he doesn't have time and how he's very hungry by the end of the day. Ask them 'how much time does he get, sitting down, that he can eat his lunch if he brings it?' and if she says '15 minutes', subtly ask something like 'so you get to the lunchroom and then there's 15 minutes?' or something.
Actually stopping by and talking to the teacher in person might work better.
I remember having a snack time all the way through elementary, do they not have that anymore?
SAHM to Magnolia May (09/10), Luke Russett (04/13) and expecting 11/16. Wife and best friend to my airman.