Bisexual star Lindsay Lohan is “extremely knowledgeable” about fashion, so says the resident expert on US TV show Project Runway.

The 23-year-old actress, whose girlfriend is Samantha Ronson, starred as a guest judge on the sixth season of the fashion show, and has been lauded by the programme’s consultant Tim Gunn.

Gunn said: “I was surprised and pleased by how extremely knowledgeable about fashion and articulate Lindsay Lohan was.

“She’s very young and can be portrayed in ways that aren’t all together flattering, and she was a true statesperson and really weighed in on the designers and what they were doing exceptionally well. And it was really a thrill to have her.”

Gunn has also praised show host Heidi Klum – who is currently expecting a daughter with husband Seal, with who she already raises three children – for her sense of style.

He told People magazine: “Heidi has incredible style no matter what condition she’s in, and she looks fabulous in everything. “She just always knows what she looks best in and she’s remarkable. I marvel at her all the time.”

Despite being a successful model, the most important thing in Heidi’s life is her family. Tim revealed: “Seal and her kids always come first, and frankly we schedule things around that. I have the greatest respect for her. She’s very, very grounded.”