At the outset of Bill Buford’s engaging new book, “Heat,” he tells of a friend who was fed a marathon six-hour meal by celebrity chef Mario Batali.

“This guy knows no middle ground,” says the friend, who spent the next several days on a detox diet of fruit and water. “It’s just excess on a level I’ve never known before – it’s food and drink, food and drink, food and drink, until you feel you’re on drugs.”

Batali himself puts his motto even more plainly: “Wretched excess is just barely enough.”

I ate at Batali’s New York City restaurant Babbo last summer. So I can attest to the truth of that credo. I enjoyed a meal so full of gluttonous excess, I was nearly taken down by the Secret Service the following day (more on that later).

So, it was with particular interest that I dove into “Heat,” Buford’s account of cooking in the Babbo kitchen. And just like the excess-craving Batali, Buford jumps headlong into what becomes a life-transforming quest for understanding authentic Italian food. How to prepare it. Who makes it. And where it comes from. That’s where “Heat” essentially becomes several books – a wonderfully entertaining narrative of life in a fast-paced New York kitchen, a travelogue of Tuscany, an in-depth profile of Batali and other great chefs, and a historical study of food.

Somehow, Buford – former fiction editor of The New Yorker – weaves all of this together in an entertaining and informative way.

For me, though, the most enjoyable parts of the book center on the time Buford spent in Batali’s kitchen. He started out in “culinary boot camp” in Babbo’s prep kitchen, dicing carrots and cubing pork. After much sweat, aggravation and some blood shed, he came to understand the complexities of the kitchen. He worked his way up to mastering the grill, which requires a dancer’s grace, asbestos arms, and a brain that can work with robotic speed and precision.

“This was starting to feel like a sporting event,” Buford writes of one dinner rush at the grill station. “Sweat was running off my nose, and I was moving fast, as fast as my concentration allowed, flipping, turning, poking, being burned, one row pointing to the right, another to the left, poking again, stacking up meat here, rushing over the branzinos that had been waiting for a spot, turning, the flames in the corner of the grill still burning, fed by the fat cascading off the new orders.”

No need to wonder how he came up with the book’s title.

Buford decided, though, that he needed a more authentic experience than Batali’s kitchen could provide. So, he headed to Italy to learn the secrets of fresh pasta making.

Then, he decided he wanted to know more about meat. So, he ended up spending some seven months in Panzano under the tutelage of Dario Cecchini, an exquisitely eccentric man who also happens to be one of the most celebrated butchers in Europe.

Buford steers clear of making any big political statements in “Heat.” After all of his immersion in food and cooking, he comes to one central notion:

“As theories go, mine is pretty crude. Small food – good. Big food – bad,” he writes.

He says the quality of food has little to do with speed of preparation, as in the common fast-food-versus-slow-food discussion, but rather in the number of steps taken to produce it. He says “small food” is made by hand, is more expensive and is harder to find. “Big food” comes from factories and is cheap and always available.

At one point, Buford returns home from one of his trips to Italy and decides he wants a whole pig so he can practice butchering it. Despite the pig’s size, it’s his own version of “small food.” He loads a pig onto his scooter and schleps the 225-pound animal into his apartment. He makes prosciutto and sausage and pork chops and ragu and headcheese. He decides to pass on a recipe that calls for the lungs.

Seven days of pig, even in this world of excess, was enough for Buford.

So, back to my night at Babbo last summer.

We ate too much (I can’t remember all of the courses, but I do recall black squid-ink pasta with spicy shrimp, pumpkin-filled ravioli, some kind of salad and, of course, dessert … or two.) I think I started with a lemon drop cocktail to drink and then there was wine, plenty of wine, and a sip or two of my husband’s house-made grappa, ladled by the server from a Mason jar.

Oh, and did I mention this feast all began at 11:30 p.m.?

By the next day, my stomach and head were begging for mercy. But we, like good NYC tourists, had tickets to an afternoon taping of the Late Show with David Letterman. The guest that day? Bill Clinton.

Feeling a little green, I took my seat. And then the band started playing and playing and playing. And my headed started pounding and pounding and pounding.

And Clinton came out and talked, about his heart attack, I think. But all I could think of was, “Oh, dear god, please don’t let me vomit right here in front of the former president.”

And then the band played some more. That was it. I had to get up.

As I jumped up, so did the Secret Service guy. I guess I looked mortified enough that I wasn’t tackled to the ground. I made it to the restroom in the Ed Sullivan Theater. And, once out of the blaring music, my stomach calmed.

But it was a close call.

All because of one night of Babbo excess.