Rationing and poverty certainly took it's toll. I was a skinny little soul, who didn't need huge amounts to eat, but was 'naughty' when I couldn't all my dinner. I remember sitting looking at the over large portion after everyone else had gone or having it served up cold for the next meal. Mum says has said since, with better understanding, that she should have trusted me to know when I was full up. She grew up when food was short and there wasn't the information out there, just what you learnt from your own parents and friends.
I did crave sweet things as I got older, but I was rationed sweetie money, tuppence on Wednesday and sixpence on Saturdays. My parents were aware sugar was not healthy.
Mum cooked from scratch. There was no other option with a limited budget. I believe the biggest problem today is in the hidden ingredients in processed food, which is easier to prepare after working hard and often cheaper. And sugar can makes things taste better and is addictive.