Standing in the shadow of the gigantic naked man is author Kathy Lette, whose head reaches only so high as his awkwardly hairy navel. He bears the pained look of a person who would rather be anywhere but perched nude on a stool in a well-lit room at the Art Gallery of NSW. She looks positively delighted to see him.

"Isn't he fabulous," she says, leaning in for a gander at the Ron Mueck sculpture Wild Man. But where to look. His thick beard? Horrified eyes? Fleshy toes? Lower back mullet? "He's not comfortable in his skin or his foreskin," Lette says. "I like the fact that he is poised on the edge of the chair, desperate to be away from here. He's so completely shocked. Where am I? Why on Earth did I let my wife talk me into this?"

London-based Lette is in Sydney as a guest speaker at the launch of the gallery's exhibition Nude: art from the Tate collection. Lette, a Tate member, takes me on a whistlestop tour of the show, which opens on Saturday.

She's impressed by the bevy of bare men on display. "Women are so used to being objectified that it is rare for us to see men naked in artworks. It's really liberating for women to be able to stroll around and objectify men for a change."

The exhibition's penis count is admirably high – just under half the paintings and sculptures feature nude men. Lette says it's a relief to see Mueck's three metre-high realistic sculpture, with all its lumps, bumps and mangled hairs. "We live in an era where we are constantly bombarded with images of physical perfection. I find him very life affirming because he is just so real."

The number one psychological trauma is waking up naked in public, she says. Number two is public speaking. Number three may or may not be the fear of dinner parties, Dutch people or cheese.

Lette's favourite work in the exhibition is Auguste Rodin's sculpture The Kiss, a passionate pash between two marble-hewn lovers. "It reminds you of the times you fell in love. We have all had that moment," she says. Ordinarily, while clothed, I say. "Speak for yourself," she says.

Learning to feel good naked is no easy task. She recommends swimming laps at a public pool. "I'm quite confident nude because I'm always naked in a change room." Lette, 57, says growing older also brings its own comforts. "You just think 'Oh f**k it, I am over 50, I am not going to be angst-ridden now'."

The exhibition's works by Pablo Picasso, Francis Bacon and Lucian Freud reveal nudes in various states of fitness, arousal and BMI. "What it teaches you is that beauty comes in all shapes and sizes and guises," she says.

"Any woman who wants to go on a diet, I would say no, just have a look around. You don't have to conform to one stereotypical form of beauty. If you feel confident in your skin, you will be beautiful."