M&C Saatchi beat Abbott Mead Vickers BBDO, DLKW Lowe, McCann London and Now, which partnered with Kindred.
The process kicked off in November last year and was handled by the Crown Commercial Service.
Once the commercial contract has been signed, M&C Saatchi will be tasked with creating work targeting 40- to 60-year-olds around smoking, drinking, eating well, exercising, stress and sleep.
The Smokefree account was previously handled by Dare and Now.
In September last year, the two agencies created an ad for the government’s Stoptober campaign that featured Paddy McGuinness and Al Murray.
Dare, whose predecessor MCBD won the Department of Health’s anti-smoking account in 2007, has partnered with Now on the strategy elements of the campaign since 2012. Dare, which is not on the government roster, did not repitch for the business.
A PHE spokeswoman said: "We have not yet appointed an agency for the Live Well brief. We have identified M&C Saatchi as a preferred supplier and will now enter into a period of commercial negotiation."
Separately, M&C Saatchi has promoted Camilla Kemp, a managing partner, to the role of chief operating officer. Clare Willetts, a business director, replaces her as a managing partner. Tom Bazeley, the chief executive, said that he is creating a "smaller, tight-knit management team".