According to its makers, one serving of Celsius can rid up to 100 calories in three hours. It works by increasing metabolism through the special 'Metaboost' formula, which also increases energy, alertness and focus - a formula that apparently works as Katie Holmes is said to be a fan.

Equivalent to two cups of coffee in one serving (containing 200mg of caffeine) as well as guarana, which is also a stimulant - it could have you bouncing off the ceiling.

Celsius is available in a seven flavours: Lemon-Lime, Ginger-Ale, Cola, Orange, Wild Berry, Green Tea Raspberry Acai and Green Tea Peach Mango.