Lexis PR saw off four rivals to land the account, believed to be worth six figures. The five-way pitch involved Lexis, Citigate Dewe Rogerson, Seventy-Seven PR, Haygarth and Edelman.
It is the first time for several years that WeightWatchers has used consumer PR agency support. Earlier this year, WeightWatchers beefed up its in-house team with the hire of Angharad Massie as PR director.
'January is the most important time of year for the brand,' said Massie. 'Since the new team was installed in June there has been a real desire to build on our PR focus for the brand.'
The new campaign will target dieters who want to shed post-Christmas weight as part of their New Year resolutions.
Lexis will target women as the core audience for the brand by getting coverage in national and regional consumer press titles.
'The key focus will be trying to recall lapsed members and attract new ones,' said Massie. 'We want to drive brand reappraisal and enrolment as part of the activity.'
The account will be headed by Lexis consumer director Fiona Jolly, who will report to Massie.