Fat people are nothing new. When Dr. Sanford Siegal began practicing medicine in 1957, he had so many overweight patients that he started treating for obesity exclusively. Exercise is all well and good, but the most effective weapon in the battle against the bulge, Siegal found, was a punishingly low-calorie diet. We're talking 800 calories a day.

Siegal's patients rarely stuck to such diets, though, because — surprise, surprise — their rumbling tummies always got in the way. Siegal said to himself, "I'm going to engineer a food that will suppress hunger." He researched natural appetite suppressants, he says, and started baking up concoctions at home.

By 1975, he had invented the perfect food: a hunger-suppressing oatmeal-raisin cookie. To this day, despite many imitators and one federal lawsuit, its precise ingredients remain secret.

Half a million patients and five cookie flavors later, Siegal has come to be known as the Cookie Doctor. "I'm not sure I ever really liked it, but that's what they called me," says the 79-year-old doctor, sitting in his Kendall office, his white hair neatly combed, his stethoscope resting on his desk. By 2002, he'd opened three medical centers in South Florida, where he would give his patients thorough physical exams and electrocardiograms, then prescribe his special diet. The diet requires eating six of his specially formulated cookies a day, plus a 300-calorie dinner, for a grand total of 800. People who stick to the diet, Siegal says, drop 12 to 15 pounds the first month.

In 2002, he was approached by a doctor named Sasson Moulavi who also specialized in weight loss. Moulavi wanted to go into business with Siegal. "This fellow was charismatic," Siegal says. "A good talker. He made grandiose promises."

Dr. Moulavi, 45, is now based in Boca Raton, where he heads a company called Smart for Life. He chuckles at Siegal's characterization of him, suggesting that Siegal might not be the sweet bespectacled man in the white lab coat that he looks like on his cookie packages.

Both parties concur that in 2002 they signed an agreement that would allow Moulavi to open franchises based on the Siegal model. It gave Moulavi the exclusive right to open weight-loss centers outside of Miami-Dade, Broward, Collier, and Monroe counties.

Soon enough, Siegal began receiving checks. According to Siegal, each independent franchise paid Moulavi ten percent of its take; the two doctors split that. Siegal maintained the longtime ritual that he continues today: Once a week, he'd go to his private bakery in a Miami warehouse accompanied only by his wife. "I lock us in," Siegal says. "When there's no one around, I mix my potion." He leaves batches of it for his team of bakers to mix into the cookies.

Siegal's recipe — referred to in press releases as a "proprietary combination of grains and other natural ingredients" or "a hunger-controlling amino acid protein formula" — is so secret, he says, that even his son Matthew, who serves as president and CEO of his company, does not know the formula. It's locked up in a safe deposit box that his son will have access to only after Dr. Siegal's death.

Siegal says that he schooled Moulavi on all aspects of his business: How to run the centers. How to screen patients. How to detect hyperthyroidism, a condition he feels is underdiagnosed. "I taught him everything," Siegal says. "Except one thing: I would not give him the recipe."

With the newfound business model, Moulavi went to work. "He was building an empire," Siegal says.

That's right, Moulavi agrees proudly. He was building an empire. He took Siegal's simple concept and expanded it from small-time operation to an international business, with dozens of franchises throughout the U.S. and Canada. Moulavi attributes much of his success to marketing savvy. He says he spent $100,000 in 2005 and $164,000 in 2006 on public relations and advertising.

According to court documents, it was in August 2002, when Moulavi opened the Boca office, that he started using the phrase "the cookie diet" to describe the program. Says Moulavi, it was hard for an entrepreneur to work with an uptight doctor, who "frequently complained" about using the "cookie diet" moniker. "He considered the term denigrating to the medical component," Moulavi says. He refers to an NBC-TV interview in which Siegal says, "I hate for it to be called the cookie diet." According to Moulavi, Siegal wanted to describe his program by this mouthful: "a diet that uses a cookie as an adjunct to losing weight."

For the most part, though, things were really cooking — until, Siegal says, he started getting letters from Moulavi's attorney. The cookies were unsatisfactory, the letters said. They were the wrong shape. They had mold. That seemed funny to Siegal, because at the same time, Moulavi's sales figures were going up and up. Siegal says that Moulavi, when confronted, brushed off the letters from the attorneys, saying, "You know how attorneys are."

Siegal adds: "I had no suspicion there was anything in the wind at all."

Then one day Siegal received a bill for a piece of bakery equipment that he hadn't ordered, indicating that Moulavi was building a bakery of his own. Siegal says he called Moulavi on it. "He told me you're an old fellow — it's just in case something happens to you."

In August 2006, Siegal received a letter saying that Moulavi was terminating his franchise agreement.

"The very same day," Siegal says, "his employees were calling, saying 'When will the cookies be delivered?' We said, 'Never.'"

Siegal says Moulavi would double his profits by cutting his franchise parent out. He'd get even more money for himself by not buying Siegal's products anymore, Siegal says.

But Moulavi maintains that there wasn't anything sinister about his motives.

"As franchises opened, operators realized that the name Siegal was not well known," Moulavi's lawyers asserted in court documents. As early as June of 2005, he stopped using the Siegal name because it "was not driving significant business."

In 2002, Dr. Siegal had registered eight trademarks to protect his business, including "Siegal Medical Group," "The Siegal Cookie," and "Siegal Diet Program" — but not "the cookie diet." The term, as Moulavi saw it, was there for the taking. In 2005, he filed a trademark application for "The Cookie Diet."

By the time their relationship fell apart in 2006, court documents allege, there were "consistency issues" with Dr. Siegal's cookies. The size and weight varied. The shapes were irregular — some looked like bites had been taken out of them. And in some cases, court documents say, the cookies "contained foreign matter such as human hairs, insects, metal fragments, and plastic filaments."

That's a low blow, Siegal says. Complete nonsense. He gladly shows off his bakery, which is almost clinically sterile, with concrete floors and employees in hair nets. It doesn't even smell like cookies, though a fresh batch sits on a tray. Siegal admits one instance of finding mold — when he changed the recipe to get rid of trans fats. The problem was quickly rectified, he says.

As the dispute heated up, Moulavi arranged for inspectors to visit the bakery. Siegal denied them entry, characterizing the "inspection" as a backstabbing ploy. "Dr. Moulavi made frequent attempts, such as this one, to learn the formulation of Dr. Siegal's diet cookie," his lawyers wrote in a complaint. Sharing it would "jeopardize the confidentiality of his trade secrets."

Siegal says he has a legal right to keep his formula secret because "our government, in their benevolence" doesn't require listing the exact ingredients of foods. The label on Siegal's cookies show that water, glycerin, and whole wheat flour are the top three ingredients; his secret protein blend likely comes from elements listed as "milk protein" and "egg white solids."

"Imagine if Coca-Cola had to give away their secret formula!" the doctor says.

"You know," Moulavi says, sighing over the secrecy, "I'm not associated with him any more because of stuff like that."

Moulavi had promised that upon termination of their agreement, he would cease any association with the Siegal diet program. So he did.

But he still wanted to capitalize on his investment. By now, "The Cookie Diet" had been featured in hundreds of newspaper articles, many diet websites, and a slew of television news segments. Dr. Siegal, in his white coat and stethoscope, had even been a subject on Good Morning America.

In January 2007, after their breakup, an NBC affiliate identified Moulavi as the creator of "The Cookie Diet," according to court documents. In the background, eagle-eyed viewers could see a Smart for Life label over the word "Siegal" on the package. Furthermore, Moulavi advertised his diet using a photo of someone who'd lost weight — on Siegal's diet. And on his websites, he planted the words "Siegal" and "cookie diet" as metatags in the source code. Now it was Siegal's turn to unleash the lawyers.

In February of 2007, Siegal filed a federal lawsuit through his company SM Licensing Corporation. He may never have registered the term "the cookie diet," he argued, but he owned it as a common-law trademark based on having invented the diet more than 30 years earlier. Furthermore he claimed that Moulavi's website amounted to "cyberpiracy." Siegal, the complaint alleged, had suffered "serious and irreparable harm."

Moulavi claimed he had registered the trademark fair and square. Now that he and Siegal had split, his marketing efforts had basically gone to waste, he said. And it cost him $4,000 apiece to change the signage and get Siegal's name off each of his franchises.

In July 2007, a judge ordered a preliminary injunction granting Siegal the rights to the term "the cookie diet." Moulavi balked and was set to appeal. The pair was ordered to mediation.

Neither side will divulge the exact terms of the agreement they finally hashed out, but each is claiming victory. In addition to selling cookies at his practice, Dr. Siegal sells them online (at CookieDiet.com) and in malls from here to Arizona to New Jersey. In fact, he says, his kiosk in the Boca Mall is the highest-grossing kiosk in the nationwide chain of Simon Property Group malls. Siegal says he was practically forced to compete with Moulavi because "we had drummed up production to tremendous volumes," and he needed an outlet for all the cookies. He says he's having fun with his newfound role as a businessman.

"Let's face it, the cookie diet is going to be my legacy," he wrote in a press release.

Moulavi now calls his program "The Smart for Life Cookie Diet." He won custody of www.TheCookieDiet.com. He touts no secret recipe, saying his cookies are organic, made by professionals at Harlan Bakeries. His stealth marketing skills are apparent: Radio DJs tout the diet, and a Sun-Sentinel writer recently blogged about using Smart for Life to lose weight for her wedding. At last count, Moulavi was running 42 franchises. Although he says he still respects Dr. Siegal, Moulavi scoffs at his thinking. "It's like saying 'I'm the first guy who invented a car.' Well, I came up with the Lexus. And I'd rather drive a Lexus than a Model T Ford."

"He went his way and I went mine," Moulavi says now. "Time will tell who's right."

Both doctors say they are too tired of battling each other to be concerned with newer competitors. But they'd better watch out: The Hollywood Cookie Diet, recently featured in various celebrity magazines, is on the rise. A box of 12 retails for $19.99.

Meanwhile, Dr. Siegal's cookies cost $56 for a one-week supply. Smart for Life offers a two-week program for $129. Pop into either doctor's office on any given day and you'll find their waiting rooms full — of chubby folks, not-so-chubby folks, even weightlifters getting ready to compete.

You could say that the personal relationship may have crumbled, but in the end, they might both be rolling in dough.