The Oprah Winfrey bounce is fading fast.

Shares of Weight Watchers International Inc. tumbled on Tuesday after the abrupt resignation of Chief Executive Officer Jim Chambers, renewing concerns about the company’s uneven comeback bid. The stock fell as much as 7.2 percent to $9.61, the lowest level since before Winfrey took an ownership stake in Weight Watchers.

Winfrey, a media magnate with far-reaching influence, triggered a rally in the shares last October when she got involved with the company. In addition to taking a stake and joining the board, she became the most visible face of the weight-loss program. Since then, she’s posted videos about her progress, helping attract others to Weight Watchers.

But the Oprah effect has only gone so far. Though Chambers managed to boost subscriber rolls in recent quarters, the company has disappointed investors with other financial results. Revenue and net income have declined in every year since Chambers became CEO in 2013. And now the board is seeking a new leader, with Winfrey’s help.

“The board clearly wasn’t happy about something performance-related,” said RJ Hottovy, an analyst at Morningstar Inc. “There must have been a difference of opinion on where to take the business the next three to five years.”

Not Orderly?

Weight Watchers will be run by a trio of executives after the 58-year-old Chambers leaves the company on Sept. 30, according to a statement on Monday. The interim office of the CEO will consist of finance chief Nicholas Hotchkin, board member Christopher Sobecki, and former Chief Operating Officer Thilo Semmelbauer. As part of the changes, Semmelbauer also has been elected to the board.

That situation -- a triumvirate leading the company -- is less than ideal, Hottovy said.

“My read is that this happened pretty quickly,” he said. “As an investor you always like to see a more orderly transition put in place.”

It remains to be seen how much Winfrey can help the company. Weight Watchers announced its deal with Winfrey on Oct. 19, saying she was buying a 10 percent stake in the company and receiving options for an additional 5 percent. The stock, which had been hammered by years of losing subscribers, more than doubled in a single day. It had closed at $6.79 the last trading day before the announcement.

But the rally has largely fizzled. So far this year, the shares have lost more than half their value.

Surprise Appearance

Since joining the company, Winfrey has tweeted about her weight loss and released a video that featured a surprise appearance at a Weight Watchers member meeting in New York. The company also plans to use Winfrey as part of its marketing campaign this winter season, when potential customers start dieting because of New Year’s resolutions.

New North American subscribers, a key measure for the company, grew 9 percent in the second quarter. That prompted Chambers to say Weight Watchers was making progress on its turnaround plan.

But it still faces long-term hurdles, including the rise of free fitness apps and changing attitudes about wellness and weight loss. Weight Watchers also has about $2 billion in debt. The company repaid a $144.3 million first-lien term loan in April, helping alleviate concerns about a default.

The challenge for the next CEO will be using Winfrey’s halo to generate better results.

“We remain confident we will deliver revenue and earnings growth in 2016,” Hotchkin said in Monday’s statement. “We are posted to enter 2017 with a revenue and earnings tailwind.”