A baker who lost nearly half his customers to the low-carb craze has tapped Dan Brown’s best-selling novel for an Atkins alternative called the “Da Vinci Diet” that he hopes will bring people back to bread.

A little math theory kneaded with biblical lore from “The Da Vinci Code” has transformed Stephen Lanzalotta into a dietary sage, answering the “carbohydrate question” with a series of lectures promoting a diet he has followed for decades to maintain a muscular 160 pounds into middle age.

Admittedly, he is neither a nutritionist nor a scholar - his background is in biology and biochemistry. But Lanzalotta argues that people have been eating bread for too long for it suddenly to be the reason everyone is fat.

“Human civilization and grain have ties that go way back. No municipal society evolved without grain, no matter what it was,” said Lanzalotta, who kneads his dough by hand like ancient breadmakers. “Not that I believe bread is one of the most sacred foods, but it is one of the most important things we can eat.”

Lanzalotta argues that bread forms the building blocks of the body and, in moderation, can lead to more stable moods, clearer thought and a rock-hard body, right down to the washboard stomach of a Renaissance statue.

The Da Vinci Diet is not published and is revealed primarily through the baker’s lectures. It consists mostly of Mediterranean foods - the foods ancient thinkers and artists ate. Fish, cheese, vegetables, meat, nuts and wine, in addition to bread - none are taboo at Da Vinci’s table.

In his diet, Lanzalotta uses a complicated formula he created that relies on the value of phi, a number discovered by ancient mathematics, used to build the pyramids, and featured prominently in Brown’s book.

The value, 1.618, is known as the “golden ratio.” It has long fascinated artists, philosophers and mathematicians.

Taking into account factors including body type, the diet typically breaks down to 52 percent carbohydrates, 20 percent protein and 28 percent fat. That’s fewer carbohydrates and more protein than current federal guidelines.

The formula also can help people choose the right foods without turning a finicky eye toward the bread humans have consumed for the ages, Lanzalotta said.

A little suspect? Maybe.

In his book “The Golden Ratio,” Mario Livio, an astrophysicist and senior scientist on the Hubble Telescope, discusses the history of the number. But Livio questions whether a diet based on it is better for the body.

“I’m not surprised in the sense that the golden ratio has been incorporated into many things,” Livio said. “But to claim that we are tuned precisely to the number, I don’t think there is particularly strong evidence.”

Lanzalotta is not alone in looking for a carbohydrate-considerate way to eat, said Dave Grotto, a spokesman for the American Dietetic Association.

Grotto agrees with Lanzalotta’s claim that most new “Atkins friendly” processed snacks on grocery shelves are mostly nonnutritive filler - low-carbohydrate cookies and treats that critics describe as tasting like cardboard.

“The bakery industry has been in essence turned on its head,” Grotto said. “But the truth of the matter, we eat because we enjoy the taste of food. And some of that gets lost in translation in low-carb foods. Some of it is God-awful.”

When low-carbohydrate diets took off amid an ever-fatter population, Lanzalotta was spending hours researching food, exploring radical dietary regimens, and finding ways to incorporate bread to make it healthy.

He actually understands why low-carb diets work and appreciates the discipline involved. The diet has its strong points, he said.

“I’m not suggesting that we eat more bread,” Lanzalotta said. “I’m just trying to look at the problems with eating only meat.”