At 28 years old and 240 pounds, Josie Raper knew she had to make a change to live a healthier life.
"It's not so easy for me," Raper of Gilbert, Ariz., told "Good Morning America."
"I would rather eat cupcakes than eat veggies and go to the gym."
After trying dozens of pills and programs that didn't work, she found Dr. Siegal's Cookie Diet online. Six months later, her size 24 frame was down to a 6.
"When I started the Cookie Diet, there was no splurging or sneaking little snacks," Raper said. "I was very strict and, to make sure that I could stay on the diet, I started the Monday of Thanksgiving so I got through every single holiday without snacking or caving in to my cravings."
Her success story landed her on the cover of People magazine.
Celebrities such as Denise Richards, Jennifer Hudson and Kelly Clarkson also reportedly tried the Cookie Diet.
Here's how it works: You eat six specially developed diet cookies with water throughout the day, not as set meals but whenever you feel hungry. Then you eat an approximately 500-calorie dinner of lean protein and vegetables.
Dr. Sanford Siegal developed the diet after years of treating obesity patients. The No. 1 factor that wrecks diets is hunger, he said, so he wanted to create a product that would control that hunger.
"It started with a formula of amino acids that I put together," he said. "But, then, I needed a vehicle for it and a cookie was an obvious vehicle; something people like. Ladies carry it around in their purse. It doesn't require refrigeration. And Dr. Siegal's Cookie Diet was born back there in 1975."
The very low, 1,000-calorie diet is designed to take weight off fast, the South Florida physician and author said.
"I know from experience that if the weight loss does not come up fast, they give up the diet," he said. "And, therefore, you don't accomplish anything."
But some experts see flaws in the diet.
"There is no credible evidence that the Cookie Diet actually helps people lose and maintain weight loss over a long period of time or that there is any health benefit from doing this," said Dr. Louis Aronne, director of the Comprehensive Weight Control Program at New York-Presbyterian/Weill Cornell Medical Center in New York City.
The Cookie Diet is missing good nutrition, he said.
"I am concerned that if someone were to follow this over the long term there are many different nutrients that they would be missing that you would normally get by eating regular food," he said.
"Good Morning America" sent the cookies to a lab to see if they matched the nutrients listed on the label and, yes, the cookies are what they say they are.
But experts say what they are isn't sufficient.
"My response is that I have treated over a half million patients over a 34-year period with Dr. Siegal's Cookie Diet," Siegal said. "I have yet to see the first case where anyone suffered any ill effect from eating a low-calorie diet. It just doesn't exist."
Obesity, he said, is much riskier than a very low calorie diet and that Cookie Diet customers take a daily multivitamin to assure good nutrition.
He never intended for the Cookie Diet to be a long-term program, he said.
But Raper, for one, has been on it for two years and doesn't know if or when she'll stop.
She's a size zero these days and no longer needs her fat pants.