In the pursuit of a representative population general fitness level, in particular weight, wasn’t on my mind at first. I was focused on a mix of age, gender and race. It only occurred to me when I saw some of the initial panels. Steve, to his credit, has a great deal of creative freedom (or, conversely and more accurately, extremely minimal guidance) on the look of the project. In one of his renderings early on in the project he had drawn a couple of the male characters as being overweight. Seeing them it occurred to me that, up to that point, none of the women were. I don’t know what the future holds for humanity in the area of healthy weight, but it stood to reason that if men could be carrying around a few extra pounds in the future then so could women. This observation was reflected in subsequent panels. As I’ve mentioned, we’re learning.
Comic Book Resources' article on body diversity.