I'm responding to your question about us being better nourished now.
We are, by and large, better nourished now. We eat food of a better quality, that's been stored and processed better, and delivered to us in much better condition.
In the past, a lack of refrigeration technology meant that foods tended to be heavily salted and processed to preserve them. If you look at a tin of Spam, for example, the meat is encased in gelatine and fat to help preserve it. For many people in the mid century, Spam would have been a staple part of their diet and more accessible to them than fresh meat, alongside other processed meats such as potted meat and sandwich pastes.
You very much do get fat from convenience, processed foods. They were just as prevalent in the past as they are now - just in a different form. That's my point.
I don't think the ration diet was a great quality diet. I would dispute that source from what I've read and heard from people who lived through the period.
We are bigger and taller now - due in large part to better quality nutrition.