It's amazing what war rationing & smoking can do for a physique!As a counter point, next time you see a film from the WWII era (or older), notice how thin everyone is. Actually, even later.
I'm waiting for an evidence-based medicine study on whether the shorter lifespans of the obese use more medical resources (and cost more) than the longer lifespans of the skinny. Seems as if the problem should be largely (so to speak) self-correcting...