In a statement, the DoH said that it had previously "run single-issue campaigns", but it would now be shifting to a strategy that reflected a "life course approach", which the government department said would deliver savings of around 25% on its media spend.
Shelia Mitchell, head of marketing at the DoH, said: "Our public health social marketing strategy takes us to the next level, adopting a life-stage based approach, which will make our campaigns more effective and save money.
"[MEC] will forego a percentage of [its] fee if they don't meet the targets set in their plans."
The DoH has prioritised four life-stage programmes; Change4Life, Smokefree, youth, and older people.
The appointment of MEC followed a tender process through the Government Procurement Service, which the DoH said, "saw applicants assessed against a strict set of criteria." The review was called in October this year.
Media buying for the DoH will continue to be handled by WPP government specialist agency M4C.
MEC will take over media planning for the DoH from 1 January.
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