Winfrey, who recently disclosed that she was taking popular weight-loss drugs as a “maintenance tool”, said on Wednesday that she would continue to work with the company, also known as WeightWatchers, “in elevating the conversation around recognising obesity as a chronic condition”.

Winfrey, who has served on the board since 2015, said on Wednesday that she would not stand for re-election at its May shareholder meeting. The shares fell as much as 29% in trading after US markets closed. If the decline in trading holds into Thursday, the stock is set to hit its lowest level on record.

WW also forecast 2024 revenue that missed Wall Street expectations, a sign its attempts to turn around several years of declining sales don’t appear to be working.

Winfrey’s relationship with the company goes back nearly a decade. In 2015, WeightWatchers struck a deal with the influential talk-show host and businesswoman who had long struggled publicly with her weight. After WeightWatchers approached her, Winfrey bought a 10% stake and joined the board. 

In advertisements, she flaunted the 40 pounds she’d lost on the programme and praised its flexibility, declaring “I have bread every day”. Her endorsement provided a much needed face-lift for an ageing brand and gave the company credibility with her large fan base.

Today, WW is struggling to keep customers as weight-loss shots like Eli Lilly & Co’s Zepbound and Wegovy from Novo Nordisk A/S soar in popularity. Last spring, WW abandoned its full-throated embrace of lifestyle change when it acquired a telemedicine startup to sell popular obesity drugs. The company also faced a backlash recently when it enlisted social media influencers for a marketing event.