subtle influences on how we eat

Brian Wansink is a Cornell researcher who does fantastic work on eating behavior (from food shopping to eating at restaurants, schools and homes).  I recommend his book Mindless Eating for some surprises on how people respond to subtle cues.

He has a project aimed at school lunches that can be very cost effective. 

I found a nice introduction to his work in an audio interview at Yale.  Short, but in two parts - the second focusing on children's lunches in schools:

part 1 (15 minutes)

part 2 (17 minutes)

...  a very entertaining speaker ...