The new campaign comes against a backdrop of changing consumer fashions and fierce competition from established rivals like Burger King and a host of newer rivals, such as coffee shops and health-food restaurants.
McDonald's announced the brave "I'm lovin' it" brand direction in June, but it is unclear quite how the US-developed campaign will translate around the world.
The new global campaign, developed in Germany, replaces the softer "We love to see you smile", which missed the mark for the fast food giant.
The campaign has been developed by long-time McDonald's advertising agency Heye & Partner, part of DDB Worldwide. The Munich-based Omnicom agency came up with the theme after a worldwide creative "competition of ideas".
When the campaign was launched, Charlie Bell, McDonald's president and chief operating officer, said: "'I'm lovin' it' will be a unifying element for the global creative approach... that connects with customers as only McDonald's can."
The "I'm lovin' it' campaign comprises five common television spots, customised for local markets, which begin to air this month in most countries.
Larry Light, McDonald's global chief marketing officer, said that the campaign would be relevant, hip, energetic and powerful. "Our advertising will connect to customers, especially young adults and moms and kids," he said.
If you have an opinion on this or any other issue raised on Brand Republic, join the debate in the .