Do the commercials on TV make a difference in your behavior?  What about the behavior of your children?  The American Academy of Pediatrics is calling for TV fast food advertisements to be banned during children's shows.   The group of 65-thousand doctors has written a new policy statement blaming the fast food industry for the nation's growing childhood obesity epidemic.   The AAP says nearly a third of American children eat fast food on a given day.   The AAP claims cutting fast food ads from kids' programing would reduce those numbers and could cut childhood obesity by nearly 20 percent.  It says there must be more than just voluntary rules to regulate how companies market food to children.  The group also calls for parents to get their kids away from the TV and provide them with healthy food and lifestyle choices.