We really have two different cases here:

1. Child is basically healthy, can digest nearly everything.  Parent
would
like to influence child to eat good food.  Yes, there's no need to be
a food cop here.  A good example goes a long way.

2. Child has very significant medical problems caused by
grains/dairy/soy/peanuts or other non-paleo food.  This is not a matter
for
"oh well, let him have some brownies, we don't want to be rigid".  Some
allergies can kill.  It is hard for children not to eat what their
friends are
eating.  But you can try to influence teachers/friends/grandparents/etc.

to not press a child to eat what will make him sick, or make him feel
like
an outcast.

And really the same for adults.  Many people on this list have had
severe
medical problems they have overcome by paleo eating.  Would you
want them to become sick again just so they can "fit in" in social
occasions?
No, I'm sure not.  This is not being a "food nazi".  It is using good
sense.

Lynnet