The 78-year-old CHANEL designer - who famously dropped 92 pounds in 13 months 10 years ago - was full of praise for the singer's "divine" voice and "beautiful" face, and he also loves how Lana Del Rey looks in photos.
Speaking to French newspaper Metro, he explained: "I prefer Adele and Florence Welch. The thing at the moment is Adele. She is a little too fat, but she has a beautiful face and a divine voice.
"Lana Del Rey is not bad at all. She looks very much like a modern-time singer. In her photos she is beautiful. Is she a construct with all her implants? She's not alone with implants."
It is not the first time Karl has hit out at fuller figures, previously slamming "fat mothers" who eat chips in front of their TV.
He previously said: "No one wants to see curvy women.
"You've got fat mothers with their bags of chips sitting in front of the television and saying that thin models are ugly."