40% of U.S. Women Are Now Obese
I blame the patriarchy.
Back then a women could look healthy and still be considered shapely or someone with a nice figure, not so much now. Anyone who knows by the time they're fifteen they're never going to match the ideal and be called fat even if they're just healthy won't bother trying to watch their weight, I've heard that from a number of my daughters' friends over the years when she was younger. Any form of dieting just goes out the window whether.
IMHo, that's at least a major factor in so many women being obese.