via UnsplashWe all know someone who can eat a medium rare steak, wash it down with a glass of whole milk & then go for a run. I’m sure you can also think of a few people who could have a head of lettuce for dinner and feel full until breakfast. I’ve always wondered why that is. Is it based on what they predominantly ate as a child? Does it have to do with the amount of exercise in their life? Are they just really unhealthy? It could be a mix of all three, and more. Who’s to say. The mystery o...