I do remember going to restaurants when I was 20 and getting meals that left me hungry. 50 years later I’m getting meals that would feed me for 3 days.
We made a trip to the Finger Lakes area of NY last month and had a meal at an Italian restaurant that is the extreme of what you are talking about.
A couple of us ordered Veal Parmesan. There was enough meat to feed at least two and enough pasta for four.
I don’t care of Italian food so I ordered a sub sandwich. It was about 18 inches long. I ate about a third of the sandwich and then just ate the meat out of the bread.
We could have fed our party of six with just two of the meals. Since we were traveling we had to waste a lot of food. It was good food just way too much for your average person.
When I was a kid, the only hamburgers sold by McDonald’s were 1.6 ounces of meat - before cooking! I believe the standard Coke sold when I was born was in a 5 or 6 oz bottle. Wonder why folks didn’t die of hunger.