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.

When Coca-Cola brought back '90s favourite Surge, it sold out online within hours. And it's not the only 'revival brand' that's been brought back due to nostalgic consumer demand. But what makes a brand re-issue a discontinued product? And what's driving Gen Y's nostalgia trip?

Coke is addictively fizzy and OJ is a deliciously sweet nectar, especially for kids. How has AquaBall – water with no sugar, artificial colours, flavours or calories – nabbed 2% market share in two short years? What’s in AquaBall’s recipe that makes it such a success?

When scanning the soda aisle in the US people generally come across three flavours – cola, lemon and lime. Oh, and root beer. But DRY Soda founder Sharelle Klaus says tastes are changing, so she's created a soft drink with flavours that cater to more adventurous palates.