Opera star Dame Kiri Te Kanawa has complained that female opera singers are starving themselves because they are under so much pressure to stay thin.
The soprano, 69, said that while her own looks "didn't hurt" her career, too much emphasis was now placed on appearance.
Dame Kiri, who previously dismissed Susan Boyle as "whizz bang", also criticised overnight singing sensations produced on the likes of The X Factor in the Radio Times interview.
She said that she deplored expectations that female opera singers should be as thin as Hollywood stars.
Dame Kiri said of today's singers: "Sometimes, they're more beautiful than their voice, and that's a bit of a sadness."
She said: "When I was at the Met (in New York), I would see these young girls, starving hungry but terrified to put on weight. They couldn't even go down to the canteen and eat in front of anyone because they were being watched. You can't do that. You've got to have beef on you if you're going to sing. I was never really hugely big, but I certainly weighed more than I do now. I ate to sing. If I started to get a bit lumpy round the middle, I would start thinking, 'Well, I must get it off,' but I was also aware of how much I couldn't or shouldn't take off."
The star, who is a patron and jury member of the BBC Cardiff Singer Of The World competition, dismissed "overnight success" in opera.
She defended previous remarks in which she said of Britain's Got Talent star Boyle: "Whizz-bang disappears. It goes 'whizz' and then 'bang'.... I'm not interested."
Dame Kiri told the magazine: "I've been criticised for even mentioning things like The X Factor, but I'm always wary of someone who is a bus driver and decides, aged 28, that they want to be a singer. There's got to be a period of study, from age 16 to 22, and then it moves along. You can't just think, 'Oh, I can sing in the bathroom, I'll be fine tonight on stage'. Not at all. There is such a demand on the voice for it to be able to produce night after night. It's the building up of the muscles that make that pair of vocal cords really work."
The star said of her own retirement from opera: "I'd much rather put the energy into getting those young people on stage. Really, that's more important to me now than hearing my own voice going through the traps."