Bacon, two types of cheese and a slick of the Colonel’s secret sauce, squashed between two fried chicken fillets. KFC’s Double Down isn’t so much a sandwich as a deconstructed heart attack. And it's appealing to our grossest desires for spectacular, unapologetic indulgence.

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?

A child kicks a ball so high it chimes the antique bell in a church tower. A woman wearing high heels and a mini dress dribbles a football down a crowded street. And an old man jumps off his motorised scooter to plays keepy-uppies on a beach. This is the McDonald's trick shot dream team.

In a bid to demonstrate how even just the sight of a Big Mac distracts people with a desire to eat one, McDonald's has released a video where people lose the ability to tell what others look like when confronted with a gigantic image of the burger.