In the latest issue of Harper's Bazaar Arabia, Jenner, who signed with Wilhelmina Models in 2010, opens up about growing up in the public eye and facing critics who say she's too thin.
"I'm constantly criticized for being too skinny," Jenner said. "I'm trying to gain weight but my body won't let it happen."
"What people don't understand is that calling someone too skinny is the same as calling someone too fat," she added. "It's not a nice feeling."
Jenner also said that life on reality television helped her overcome her habitual shyness.
"I used to be so shy. I used to never talk, just sit back and do my thing," she told the magazine. "I am still pretty shy, but I've gotten much better because I'm always on set for photo shoots and I'm always filming with my family."
Kendall's Harper's spread has been a hit with her half-sisters -- Kim Kardashian weighed in on her blog, calling Jenner's work "stunning."
"She did an amazing job and the photos turned out absolutely gorgeous."