The singer and Strictly Come Dancing judge will front the £28m campaign, which is the first creative led by Saatchi & Saatchi and marks a fresh positioning for Weight Watchers based around ‘play’.
The pop-video-style ad stars 180 Weight Watchers members, who take turns lip synching the song lyrics, which are penned from their own stories.
The song, Do It Our Way (Play), launches with a full three-minute spot on 1 January across all commercial channels between 6.45pm and 7pm. The song will also be available to download from iTunes the same day, with 25p from each sale going to Weight Watchers’ chosen charity, Tommy’s.
Andrew Knight, senior vice-president, Weight Watchers UK said: "This ad marks the beginning of a new loud, proud and playful Weight Watchers brand campaign. It blends our members’ real life stories and experiences about what losing weight means to them with Alesha’s big personality and voice. It’s the biggest expression of weight loss success we’ve ever delivered."
Richard Huntington, director of strategy at Saatchi & Saatchi, which won the account in August, added: "Our objective in relaunching the Weight Watchers brand is to make it feel more relevant and inviting to millions of men and women across Britain who want to lose weight. The new brand idea, ‘Play Weight Watchers', celebrates the joy of weight loss and their belief that it is a serious business but doesn't need to be a miserable one."
Following the initial full-length TV ad, Weight Watchers will air a series of 30-second spots, with a run of separate ‘real life stories’ of key members from the pop video throughout January.
The ‘Play Weight Watchers’ campaign will be supported by local marketing and a social media campaign, including the launch of a fully branded Weight Watchers YouTube channel and Play Weight Watchers microsite.
Separately, Weight Watchers is tying up with LA Fitness in a 12-month deal from January, including a joint ‘Get Active’ campaign, timed to coincide with the run up to the Olympics.
Alesha Dixon, who is also a brand ambassador for LA Fitness, added that diet and exercise wasn’t just about looking good. "It’s first and foremost about being healthy, and both Weight Watchers and LA fitness share this philosophy. We’ve lots of innovative ideas in store to put health and fitness back at the forefront of people’s minds."