Bertinelli, clad in a white lab coat, tells viewers a "major clinical trial ... run by some serious lab geeks" found dieters using the Jenny Craig approach lost twice as much weight as those using the nation's largest weight-loss program.
The problem was no such study existed, Weight Watchers said in a federal lawsuit filed in January. At that point, the campaign had run for less than a month on TV, in print and online, and a federal judge in Manhattan temporarily barred Jenny Craig from broadcasting, publishing or distributing the ads.
Weight Watchers said Jenny Craig's claim was not supported by fact or science.
The purported trial actually was two separate studies, each comparing one company's program to do-it-alone diets. And they were conducted 10 years apart, looked at different outcomes and didn't include Weight Watcher's current diet methods, Weight Watchers said.
Jenny Craig CEO Patti Larchet said in a statement that her company - a subsidiary of Swiss food maker Nestle SA - admitted no wrongdoing and has agreed not to compare the results of its own research to past data about the Weight Watchers method.
"In fact, Jenny Craig has such faith in its program and feels so confident about its performance in clinical trials that we challenge Weight Watchers to compete directly with us in a head-to-head clinical trial," Larchet said. "If Weight Watchers refuses to take up our challenge to compete head-to-head in a new trial, we suggest that they offer consumers up-to-date rigorous clinical studies to support the advertising of their current program."
Weight Watchers, which is based in New York, also alleged the Jenny Craig ads' launch was deliberately timed at the height of the diet season. Late December is a crucial period for both companies because it's when people are mostly like to seek help losing weight.
"We are pleased that Jenny Craig will no longer be allowed to continue using this false and misleading advertising, now and in the future, and to put this situation behind us," Weight Watchers President and CEO David Kirchhoff said in a statement.
The feuding weight-loss companies use different approaches to help their clients shed pounds. Jenny Craig's method is based around company-provided food and one-on-one meetings with a coach. Weight Watchers uses a points-based system for food and exercise and offers group meetings.