Margarine melts more consistently than butter due to its chemical makeup. Douglas Sacha/Moment via Getty Images My mother loves butter. It is the primary fat I ate growing up. She smeared it on any kind of bread, potatoes, nut rolls or coffeecake. She baked with it exclusively. When I was studying nutrition in college, I had a teaching assistant who recommended margarine over butter. I was shocked – and wondered about the difference between the two. It was one of the things that sparked my int