Weight Watchers’ shares got another boost from the falling weight of Oprah Winfrey, the company’s backer and most famous customer.

The shares climbed as much as 14 per cent after Winfrey announced that she’d lost 40 pounds using the program. The diet company, whose shares had fallen 54 per cent this year before Thursday’s surge, is unveiling new TV ads featuring Winfrey that tout her weight loss. The media magnate and talk-show veteran became a centrepiece of Weight Watcher’s comeback plan last year when she bought a stake in the company and joined the board.

In October 2015, when Weight Watchers first announced its deal with Winfrey, the shares more than doubled in a single day. Though the previous rally has faded, Winfrey’s subsequent endorsements of Weight Watchers have given the stock temporary jolts.

The shares gained 27 per cent over two days last December when Oprah tweeted a video about using the weight-loss program, and there was a 20 per cent bump in January after Winfrey said she had lost 26 pounds while still eating bread every day.

The latest marketing push begins next week, just before the New Year’s holiday. The coming weeks are critical for Weight Watchers: The company typically adds about 40 per cent of new customers in the first quarter, when resolutions push people to seek out diets.

The stock climbed as high as $12 (£9.80) on Thursday, its biggest intraday gain since 4 November.

Heavy Competition

Weight Watchers has been hit hard by the rise of free fitness apps, and a move away from strict calorie counting among dieters. But Winfrey’s wide-ranging influence has brought new life to the brand. Weight Watchers has added subscribers for three straight quarters after years of declines.

The New York-based company hopes that Winfrey’s new ads, which emphasise that she still enjoys pasta and tacos, will convince dieters that its updated program is an effective weight-loss tool.

“It’s vitally important that Oprah is living the program and articulating it in a way that’s authentic,” said Maurice Herrera, the head of marketing at Weight Watchers. “It really connects with prospective members.”

Despite the subscriber gains, it’s been a rocky year for Weight Watchers. The company has billions in debt, and its stock is heavily shorted. In September, chief executive Jim Chambers announced he was leaving after about three years at the helm. That sent the shares plummeting to their lowest level in nearly a year.

Interim chief executive

Chambers had been working to turn around the company, an effort that included revamping its nutrition program and adding a social-networking component to its app. Now, Weight Watchers is being run by a trio of executives who constitute the “interim office of the CEO.”

Business news: In pictures Show all 13 1 /13 Business news: In pictures Business news: In pictures Flybe collapses Airline Flybe has collapsed. All future flights on the Exeter-based airline have been cancelled – leaving more than 2,300 staff facing an uncertain future, and wrecking the travel plans of hundreds of thousands of passengers. The chief executive, Mark Anderson, said: “Europe’s largest independent regional airline has been unable to overcome significant funding challenges to its business. AFP via Getty Business news: In pictures Future product placement will be 'tailored to individual viewers' Marketing executives say that product placement in films and televison shows on streaming services such as Netflix may be tailored to individuals in future. For instance, if data shows that a viewer is a fan of pepsi, a billboard in the background of a shot would host an advert for pepsi, while for a viewer known to have different tastes it could be for Coca-Cola Paramount Business news: In pictures Corbyn wishes Amazon a happy birthday In a card sent to Amazon CEO Jeff Bezos on the company's 25th birthday, Labour leader Jeremy Corbyn writes: "You owe the British people millions in taxes that pay for the public services that we all rely on. Please pay your fair share" Business news: In pictures No deal, no tariffs The government has announced that it would slash almost all tariffs in the event of a no-deal Brexit. Notable exceptions include cars and meat, which will see tariffs in place to protect British farmers Getty Business news: In pictures Fingerprint payment NatWest is trialling a new bank card that will allow people to touch their hand to the card when paying rather than typing in a PIN number. The card will work by recognising the user's fingerprint NatWest/PA Wire Business news: In pictures Mahabis bust High-end slipper retailer Mahabis has gone into administration. 2 Jan 2019 Mahabis Business news: In pictures Costa Cola Coca-Cola has paid £3.9bn for Costa Coffee. A cafe chain is a new venture for the global soft drinks giant PA Business news: In pictures RIP Payday Loans A funeral procession for payday loans was held in London on September 2. The future of pay day lenders is in doubt after Wonga, Britain's biggest, went into administration on August 30 PA Business news: In pictures Musk irks investors and directors Elon Musk has concluded that Tesla will remain public. Investors and company directors were angry at Musk for tweeting unexpectedly that he was considering taking Tesla private and share prices had taken a tumble in the following weeks Getty Business news: In pictures Jaguar warning Iconic British car maker Jaguar Land Rover warned on July 5, 2018 that a "bad" Brexit deal could jeopardise planned investment of more than $100 billion, upping corporate pressure as the government heads into crucial talks AFP/Getty Business news: In pictures Spotif-IPO Spotify traded publically for the first time on the New York Stock Exchange on Tuesday. However, the company isn't issuing shares, but rather, shares held by Spotify's private investors will be sold AFP/Getty Business news: In pictures French blue passports The deadline to award a contract to make blue British passports after Brexit has been extended by two weeks following a request by bidder De La Rue. The move comes after anger at the announcement British passports would be produced by Franco-Dutch firm Gemalto when De La Rue’s contract ends in July. The British firm said Gemalto was chosen only because it undercut the competition, but the UK company also admitted that it was not the cheapest choice in the tendering process. Business news: In pictures Beast from the east economic impact The Beast from the East wiped £4m off of Flybe’s revenues due to flight cancellations, airport closures and delays, according to the budget airline’s estimates. Flybe said it cancelled 994 flights in the three months to 31 March, compared to 372 in the same period last year.

The ads rolling out next week show Winfrey doing yoga and cooking pasta. As consumers have changed their perception of wellness, Weight Watchers has pivoted to emphasize that weight loss and indulgence aren’t necessarily mutually exclusive. Winfrey will hammer that message home, Herrera said.

“People want to know what’s on her mind and how she’s living her life,” he said. “This will definitely get people’s attention.”