Whether it’s resisting the bread basket or combating the urge to order dessert, Simon Doonan has a theory: Gay men, much like French women, have a gift: Both indulge in moderation.

Doonan’s argument is similarly sassy. Gay men are adept at perpetually fitting sample sizes, unlike straight men who wear Tommy Bahama shirts and “literally eat their faces off.”

Doonan, a Slate humorist and creative ambassador-at-large for Barney’s New York, wants to help straight men end (and tease them for) their slovenly ways.

Sure, his case is theatrically over-the-top, but so is Doonan. (This is a man who, in the late 1970s, made a name for himself by putting stuffed rats into a chic window display on Savile Row.)

Those who read this book should, in fact, judge it by its cover: pink florals and all.

Nobody’s safe from the well-heeled Brit’s desire to offer up style advice, including American politicians. Politicians, he told Slate’s Jacob Weisberg last month, wear unremarkable clothes on purpose.

“There’s no room for style in politics,” he says. “The only stylish politicians are dictators.”

Simon Doonan (Evan Agostini/Ap)

Doonan would know Obama’s style firsthand. His book concludes with a whimsical chapter about receiving a call from former social secretary Desiree Rogers, who asked him to decorate the White House for Christmas in 2009. In typical Doonan fashion, the extravaganza explodes in a flurry of drag queen ornaments and skim eggnog, but the lesson remains: Be yourself and resist the guacamole.

Doonan will be at the W Hotel Rooftop Altitude Ballroom at 7 p.m. Wednesday for a book signing. RSVP at whappenings@brandlinkdcrsvp.com.