Fashion & Beauty

So fab, dahling

In 2004, Mireille Guiliano’s book “French Women Don’t Get Fat” took the country by storm, convincing American women that the French held the secrets to our dieting woes. Simon Doonan, creative ambassador-at-large of Barneys New York, fights back this month with his new tongue-in-cheek book, “Gay Men Don’t Get Fat.”

“French women always set themselves up as arbiters of style, and every American woman thinks that every French woman is Coco Chanel,” Doonan tells The Post. “But this is not the case. French women only think they know everything. Actually, it’s the gays who do know everything.”

So how did gay men become the ultimate tastemakers? “Being the outsider automatically gives you a more creative, more intuitive view on life and style and magic,” says Doonan.

“Being gay is an insane, fabulous gift,” he adds. “It’s the ultimate Whitman’s Sampler.” Here are his tips on what straight women can learn from gay men.

1. Eat a healthy mix of gay and straight foods.

“Here’s an example of gay foods: macaroons, lettuce, sushi,” Doonan says. “Those are all super-gay. But you can’t live on macaroons — you’ll just explode with gayness if you try. A beef burrito is about the straightest food you can get. If you want to be healthy and trim, you have to combine the two. Have a steak. But instead of having french fries with it, which are very heterosexual, what you need is a nice, fluffy gay salad.”

2. Surround yourself with as many gay men as possible.

“Being a fag hag is a great way to stay skinny,” says Doonan. “Gay men are always on the go. If your friends are all gay men, they’re always twirling in one direction or another. If you’re following them, you’re automatically burning calories.”

3. Cheat for the camera.

“We live in a world where people are constantly taking your picture,” says Doonan. “Bang! It’s on Facebook before you’ve even gotten home and taken your wig off.” To look your best, follow Doonan’s tips for posing — saying “cheese” isn’t one of them: “The least you can do is get your face arranged in a pleasing configuration. The way to do that is to say the right word. Allegedly, Kate Moss always says ‘chin on the ledge’ to remind herself to arrange that fabulous bone structure as though she’s placing her chin up on a ledge. Allegedly, when people are taking Iman’s picture, she says the word ‘douche,’ but in a really attractive way.”

4. Channel your inner child-pageant queen.

“Child pageants are great for staying skinny,” he says. “You’ll notice that the kids are all skinny and the moms are all huge because the kids are the ones tap dancing their brains out and rushing from one end of the runway to the other. The mother just sat there in a folding chair in the hotel’s function room.”

5. Respect your expiration date and stay away from surgery.

“All these creams and jars that women are bombarded with that say ‘anti-aging’ — to me that seems so absurd and hilarious that you think you’re going to reverse time,” says Doonan. “The most important thing when you get older is to stay fit. Join a circus, learn to trampoline, ride a bicycle. Learn tap dancing! If you become bovine, then you’re toast.”

6. Know your lighting.

“It’s a Tennessee Williams kind of thing,” says Doonan. “Gay men are very influenced by Blanche DuBois. She always understood that it’s all about throwing a little chiffon scarf over the nearest light bulb to make sure that you have some nice peach light. Preferably backlight.” His golden rule? Get a dimmer. “We gays have never met a dimmer we didn’t love,” says Doonan. “When I go to meet the creator, I fully intend to have the light inside my coffin on a dimmer.”