But Jenny Craig has a strategy to bring profits back up, says spokesman Brian Luscomb.

graphic: bloomberg news

Jenny Craig's sales slumped in 1998, but the company has a strategy to increase profits.

"For the first time in the company’s history, our dieters can buy meal supplements instead of the regular meals," he says.

The company still charges a $49 registration fee and clients continue to pay $72 to buy a week's worth of Jenny Craig products, all in an effort to develop a "healthy relationship" with food.

Luscomb defended the requirement to purchase Jenny Craig foods.

"It’s helpful at the beginning of a diet to not have to make the food choices for yourself," he says.

mass marketing anxiety

Despite their financial success, commercial diets like Weight Watchers often don’t meet their promises.

Diet failure rates hover between 90 and 95 percent, according Jeanine Cogan, a congressional science fellow for the American Psychological Association. But many of the major companies don't disclose their statistics on success.