Buying food only from the outside edge of the supermarket, where the fresh produce, milk, juice, etc. are displayed, in order to minimize the purchase of packaged products and to maximize eating healthy
He: Your boyfriend's really into ecology these days!
She: Yeah, he's even into outside-edge shopping?
She: He only buys stuff that is displayed around the outside edge of the supermarket because he thinks it's ecologically less damaging than the rest of the stuff there -- and better for you.