the dinner plate from 1960...which was 9 inches in diameter...
is now 12 inches ...
According to Alex Bogusky in his book.."The 9-Inch "Diet"
He also ststes that America has been suffering from a severe case of gigantism. He chronicles the explosion of over-sized beverages that have pooped up since the late '80s'. Over the years the large became the medium and the medium became the small and the small became the childs' cup.
The average bagel has doubled in diameter since the 1980s'.
Food portions are typically at least 25% larger than those in Europe.
So some things are not dwindling.
Obesity for one.