July 21st is National Junk Food Day and that is the perfect excuse to indulge in our favorite guilty pleasures, from crispy fries to juicy burgers. But while we’re enjoying these treats, it’s important to explore the journey the by-products of our junk foods take (like what happens to the oil they are cooked in which is aptly called used cooking oil or UCO), and how the journey of those by-products contributes to a more sustainable