That’s my biggest issue, normalization.
Look at high school pics from the 1940’s.
She would be an absolute outlier.
I don’t know the exact causes, but something is definitely wrong.
I dare say it’s mostly because of the lack of home-cooked meals. I was born early 50’s and there were very few fast food restaurants around. The grocery stores had very few prepared foods (Swanson tv dinners lol). Now look at it - take-out food, restaurants everywhere, fast food joints, and the areas in grocery stores for prepared foods far exceeds the fresh foods.
We went out for fast food once a year. A&W. They roller skated up to your car and put the tray on your window lol. We sure gave up a lot when we took the moms out of the house and put them into the rat race. They called it equality. Many I know called it a rip-off, but the government certainly hauled in more taxes!
Sometime back (2000?) I lived in Alabama but happened to be in California at a Major League baseball game. One of my daughter’s acquaintances asked me if everyone was fat in Alabama. I said no. I felt like asking “how about that Hispanic guy over there?” but held my tongue. There was no obesity epidemic back then. There sure is one now. Something is very wrong.