We are creatures. We have a link with a native habitat just like every other species. Throughout most of human history, physical activity was unavoidable, calories were scarce and hard to get. In the modern era, calories are unavoidable, physical activity is scare and hard to get. The traits that allowed our ancestors to survive, and let's face it, the survival of our ancestors is the reason that we're here because the people who don't survive and make very crummy ancestors, are our traits. But they're very much at odds with the modern environment.