Ms Voight was supposed to sing the lead in Ariadne on Naxos, but Peter Katona wanted to have the lead sing in a black evening dress - and decided that Ms Voight would look unattractive in that outfit. So instead he replaced her with a more slender singer.
Other opera houses relish Ms Voight's performances and have no issue with her weight. The Metropolitan Opera House in New York will be featuring Ms Voight in a few months in a production of "Die Walkuere", where she co-stars with Placido Domingo.
Wht is ironic is that after I wrote this up, I was in a creative writing class where this case was explicitly brought up as a situation where the news reporters "left out" key information in their story - i.e. the woman's actual weight! Our teacher implied that the public had a "right to know" her weight so they could understand the story. I was horrified!
It was bad enough that people were judging her based on her weight alone. To say that the whole world now should know her exact weight - and I'm not sure exactly how this teacher thought the reporters should get their hands on this private information - was quite abhorrent to me. A weight is a personal's private medical information, and if someone wishes to keep it private, they should be respected.

Lisa Shea's Library of Low Carb Books