IF you are having recess after lunch then you are going to be not healthy. Your grades and health will go way down. People want to stay nice and healthy but some people just want to eat very quickly and go to recess but that is a really bad idea.
I honestly think it does not matter whether you run around before or after you eat. Either way, The kids are getting their exercise and will be tired out after running around for 30 minutes. That way, The classroom will be quieter and less of a pain for the teachers.