Lindee Lee Bingham and Sandy Martucci have tried so many diets they can't keep track of them. But the two sisters from Bergen County, N.J., noticed that all diets have something in common: They require dieters to keep track of something -- calories, carbohydrates, fat grams, or glasses of water.

The sisters invented a gadget -- the Cal-Carb Clicker -- that they hope will be a hit with the dieters of America, and the weight-loss chains that serve them.

Bingham and Martucci hope to tap a market generating more than $50 billion in sales a year. Last year 26 percent of American women and 19 percent of men said they were on formal diets, according to the NPD Group, a market research firm based in Port Washington, N.Y.

The sisters have been developing the idea of calorie and diet tracker for more than a decade. They got their first big break last fall, when Curves International, the women's exercise franchise chain with 10,000 locations worldwide, placed an order for 30,000 customized Clickers.

As of this week, Curves has sold close to 20,000 Clickers at $9.95 each. "They did sell well," said Ashleigh Schoenfeld, the head of new products for Ideas in Action, the company that supplies Waco, Texas-based Curves with retail products. "It's a great weight loss tool for the Curves program."

The sisters and the company they created to market the device, JC Product Design LLC of Hillsdale, N.J., also sell a different version of the Cal-Carb Clicker for $19.95 on their Web site. However, they believe the future of the product is in wholesale deals such as the Curves sale, rather than in individual sales.

In recent months, Bingham and Martucci have attracted interest from outside investors, including Les Fox, a Wyckoff, N.J., resident who made millions as the author of the best-selling "Beanie Baby Handbook." Fox invested several thousand dollars in the company and signed on as the vice president of marketing.

Fox said he's sold on the Clicker because "it's the only patented carb and calorie countdown device." He said the "countdown" feature is what makes the Clicker special.

"You can use any countdown device to count up, but this lets you count down," he said.

The device is about the length of a thumb and can be programmed with the total allowed number of calories and carbohydrates. As the dieter eats during the day, he or she clicks buttons on the device to subtract the amounts consumed. A third button allows the dieter to "count up" as he or she drinks glasses of water.

"We purposely made it so the water count goes up rather than down, because that's an accomplishment when you're drinking the water," Bingham said.

Fox said he's seen other, more expensive devices that require a computer and software, but he believes the Clicker beats them because it's easier to use.

The customized Clicker produced for Curves is the fourth evolution of the sisters' original idea for a diet-counting device. They began working on their idea about 10 years ago, and originally produced a stainless steel bracelet with a digital countdown device imbedded in the bracelet. They sold the bracelet, priced at $39.99, at gift shows, at a trunk show at Bloomingdale's flagship store in Manhattan and on their Web site. A product-manufacturing company with contacts in China spotted the bracelet on the Web site, and approached the sisters about putting their digital countdown technology in a less expensive, plastic gadget.

The sisters credit their mother, Olga Bauer, with providing the inspiration for their invention about 10 years ago. At the time, the sisters were following the Weight Watchers diet, a regimen that requires dieters to count "points" -- with different food having different point values. Bingham and Martucci commented to their mother on how hard it was to remember to keep track of their points. Bauer said "Wouldn't it be good to have something you could wear that would keep trackfi"

"So we started off with the bracelet," Martucci said. "We spun our wheels a little with that. It looked pretty, but it didn't work out too well."

"It was very expensive to make, and we thought the digital readout was a little too small," Bingham said. A process of trial and error resulted in the current device. "We're 1,000 percent satisfied with the way this one came out," she said.

The Cal-Carb Clicker is "patented as a nutritional aid," Bingham said, "and it can be used with any kind of program. The Curves version is using it for calories and carbs, but if someone was on a low sodium diet, they could use the top number to keep track of sodium. Or they could use the middle number for fats."

The sisters, and now Fox, have been pitching the device to other weight-loss companies, including Weight Watchers and Atkins Nutritionals Inc. They also hope to eventually land a spot on a home shopping channel, or to feature the product in an infomercial.

Bingham and Martucci haven't quit their day jobs yet to pursue their Cal-Carb Clicker dream. Martucci helps run the business her father founded, Ken Bauer Kitchens in Hillsdale. Bingham is a piano teacher and AmeriPlan medical plan broker.

The sisters estimate that they've invested about $100,000 in their invention, and say they will need to sell millions of the gadgets to recoup their investment. Fox believes that is possible, if they can tap into the millions of Americans on diets. "Having something you can use to count down your calories and carbs helps you psychologically to stay on a diet," he said. "And we hope that millions of people agree with that."

This story appeared in The Daily Herald on page B2.