With McDonald's challenged by fast food chains like Chipotle and Subway – which emphasise fresher ingredients and let people choose what goes into their products – the burger chain is expanding the "create your own taste" option. But can it boost sliding sales?

People want big brands to consider the planet as well as their patrons. Chipotle is ahead in this game, with the recent release of their app-game hybrid campaign The Scarecrow demonstrating the power of emotional storytelling.

Gen Z had eluded Subway. Teens are watching less live TV, so they don’t see its ads, and they don't like direct advertising. So Subway launched sitcom The 4 to 9ers, and the first season attracted 18 million viewers. But who wants to watch a TV show created by a fast food chain?

We’ve all experienced ordering food at a restaurant and having to wait ages for it to be ready. Aiming to solve the problem, McDonald’s is running a test programme with the promise of delivering drive-thru orders within 60 seconds - or customers receive a free lunch.