you can't really judge, you'd have to take someone from 1950 and outfit them in whatever you deem acceptable now and THEN judge.
Changes in nutrition, medical procedures and plastic surgery (like others have mentioned) have an impact. In 1950 a wasp -waisted figure and a slightly fuller face were preferred. Now a more athletic/less curvy and angular face seems to be preferred in women
For men a less bulky build and androgynous features seem to be preferred.

I don't think people have changed as a species. What you are perceiving is a change in fashion rather than an actual, physical change.