But even odder was Bruni's love-hate relationship with food - something he now acknowledges in his new memoir, "Born Round: The Secret History of a Full-Time Eater."
The revelation isn't exactly shocking but it is unusual. Bruni, the man who had volunteered to eat out six nights a week, had obsessed about his weight for most of his life. He had battled bulimia briefly, toyed with laxatives and torpedoed many a diet - all the trimmings for his third book.
"I remember thinking if I look up after a couple of years and I am right, and I have figured out a better way to manage my relationship with food, it's probably a pretty interesting narrative how I got to this point," Bruni says about the moment he decided to take the job.
If waist size is an indicator of success then Bruni, with his close-cropped hair and athletic build, has been wildly successful curbing his prodigious appetite. After ballooning to around 275 pounds and sporting 42-inch pants while covering a presidential campaign in 2000, Bruni can now take a moment to brag.
He wears size 34 jeans and doesn't look round anymore - despite eating his way through approximately 700 restaurants in New York alone during his stint as critic that came officially to an end this month. Sadly, Bruni left with a whimper instead of a whammy Wednesday, his final review about an unremarkable joint in the East Village known for its fried chicken.
"I like eating, and I prefer eating in great volume to eating in minor volume," Bruni, 44, says in an interview at a wine bar on Manhattan's Upper West Side near his home. "No question. Having been through everything I describe in the book, I am fully aware and I struggle to remain conscious of the consequences."
The consequences have plagued Bruni throughout his life but they came to a head when he decided in April 2004 to leave his post as Rome correspondent and tackle restaurant reviewing in New York, perhaps the most important dining city in the world and one filled with know-it-all foodies.
For Bruni, danger loomed. A sea of calories awaited him. He took the plunge - one that has local restaurateurs now scratching their heads since learning Bruni's anguish over food.
"It's like an alcoholic becoming a winemaker," says John Fraser, whose New York restaurant Dovetail faired exceptionally well under Bruni's withering gaze, earning three stars.
Bruni knew the task ahead of him was great. He adjusted and learned on the job. He "ate more widely and in a much more inquisitive and thoughtful manner." He developed a "frame of reference" that was "extremely broad and unusual."
He not only wrote about places in New York but he also ventured across America and Europe, alerting readers to gems such as Alinea in Chicago. Bruni could at times be snarky in his reviews but he was mostly right when he decided to bring out the knives, according to chefs.
Sometimes, restaurants caught him; sometimes they did not. A well-worn picture floating around of a heftier Bruni aided his cause to slip into restaurants unnoticed.
"We had the fat picture. You would never guess that's the same person," Fraser said about Bruni's most current photograph posted on the food blog Eater.com and the one found inside the cover of his book.
His style of writing attracted many followers. Not everybody loved him but they definitely talked about him. As Bruni evolved, people noticed, chatting about him at cocktail parties, said Jennifer Baum, an influential restaurant publicist who has never met Bruni but had about a dozen of her restaurants reviewed by him.
"It stepped beyond the walls of the industry," Baum said, referring to his reviews.
Baum, like other food publicists, kept a wary eye on Bruni, who once slapped around one of her celebrity chef clients, Bobby Flay, taking a star away from Mesa Grill in Manhattan. Baum wouldn't comment about her client's reaction to Bruni's takedown, but she said he was fair and honest.
"There are some restaurants that opened where people didn't pay attention and those restaurants should be shouted out," she said. "He went into the venerable restaurants and made sure they were paying attention."
And the weight? Not only did Bruni beat back the calories through rigorous exercise and moderation, he also beat back the doubters in a city filled with them. Bruni, according to some of the toughest critics in town, prevailed.
"When he started out, Frank famously knew almost nothing about restaurant criticism, and it showed," GQ magazine food critic Alan Richman said. "He was saved by his writing - which is exuberant and charming, by his indefatigable work ethic and by his instinctive ability to write brilliant criticisms of restaurants that he either hated or loved. I'm not sure if any restaurant critic has been better at praise."
Richman, who once eviscerated one of the most famous chefs alive, Jean-Georges Vongerichten, in a scathing article for his magazine, said it's too bad Bruni is giving up his reign as most feared critic in New York.
"What I regret about him leaving now is that he finally has that skill, something that comes with scrutinizing thousands of plates of food," Richman said. "He's at his peak."
Bruni isn't sorry. He can finally exhale after crafting about 270 reviews - visiting some spots more than once - for the newspaper that could turn a restaurant into a massive hit or major flop. He decided to end his run as critic because his "energy would fade or was fading."
Bruni says his old gig wasn't just about eating. It was also about coordinating the meals - all the time. He always dictated the schedule, calling himself a "bully." He decided on time and place. Eating was always on Bruni's terms.
Sometimes his energy would flag. The obligation to be a "vivacious and interesting host" was grueling, he says.
"It's a little bit emotionally exhausting," Bruni remarks after taking a sip of Pouilly-Fuisse and greedily eyeing a plate of cheese, toasted bread and grapes the owner sent out and which Bruni immediately insisted on paying for.
Don't take pity on Bruni. He doesn't expect any. "This job was a cake walk compared to covering the presidential campaign."
These days, Bruni is relishing being a civilian. He imagined he'd simply go home and get food delivered (he's a horrible cook). But no, he's been eating out often, following his natural inclination.
His routine has definitely changed, though. On three consecutive nights he had chicken. Why? Because he could.
"It was a sort of a little petty rebellion against the need to try everything," he says. "I am still totally adjusting."
Bruni fans can continue to read his work. He begins writing for the Times' Sunday magazine in October, where he'll delve into politics, culture and even some food.
First, though, he has to promote the book, a large portion of which he cranked out last year on vacation in Italy and Scotland.
And the former reviewer has to wait to see if reviewers will embrace his book or pan it.
Bruni, of course, knows the drill.