The agency has been called in for a one-year retainer around the scheme following a pitch, replacing incumbent Weber Shandwick.
It will be helping to create an initiative to further engage youngsters and adults in Active Kids, in which nurseries, schools and other accredited groups can redeem vouchers for sports equipment.
The M&C Saatchi team will be led by MD Jamie Wynne-Morgan and report to Jat Sahota, Sainsbury’s head of sponsorship.
Wynne-Morgan said the agency was involved with creating a campaign ‘in which those in schools and organisations will be able to more actively take part’, though he was unable to reveal details of the work.
‘It’s about adding an incentive for them to get more involved and it should culminate in a big national event,’ he added.
‘The scheme doesn’t need to be fundamentally changed, we’re just adding to it, and should fit in with Sainsbury’s overall message of getting healthier and being active.’
The scheme, which is in its eighth year, will go live in February.
Sahota said: ‘Active Kids has been one of our most successful campaigns and, while it continues to grow, it’s great to bring in some fresh thinking.’