When I was teaching, the member of staff who looked after the archives, showed the school a film of a sixties sixth form sports day. Every single child and member of staff was extremely slim and contrasted clearly with the children in the audience who were all sizes from normal to very large.
I used to show the sixties’ film ‘Lord of the Flies’ when I taught the book. Again, the child actors looked like whippets and and protruding ribs, all except Piggy, the overweight boy who, in the film, looked about average for today.
So, yes, in my memory, and documented by film, people were much slimmer in the past.
We ate less at each meal and never between meals. I remember mum would share ten fish fingers or a Vesta curry between four of us. We also walked further than children do today. I liked to run everywhere as a kid and ran and walked mile to school and in the holidays.
Despite my best efforts to get my own children to eat sensibly and to take exercise, as adults they both struggle with their weight while I have stayed slim.
It is a conundrum. Our modern lives are killing us with plenty. I think the greatest deprivation the present age offers is that of willpower and volition.