Kraft International's London office, where Johnson was based, oversees operations across western Europe.
Kraft has pledged to stop advertising some of its products to six to 11-year-olds in the UK, extending its long-term advertising ban to children aged under six. It has also slashed salt content across the Dairylea range.
International Obesity Task Force director of policy and public affairs Neville Rigby applauded Kraft's commitments in the US and UK, and hoped they would be applied even more vigorously across Europe.
The US food group's brands include Philadelphia and Kenco.
Kraft would not comment on the vacancy.