A thirst-quenching 100 million cuppas are consumed each day in Britain, making black tea among the most consumed drinks in the world.
As a guide, a 3.5oz (100g) serving of milk chocolate has around 21mg while the equivalent amount of dark chocolate (70-85% solids) has 80mg.
Some flavoured waters contain 60-125mg of caffeine per bottle (254ml/8.5 fl oz), particularly those marketed as caffeinated waters designed to give an energy boost.
Green tea contains powerful antioxidant EGCG and nutritionists believe it could boost brain function and protect against disease.
Many ice creams contain zero caffeine, being essentially frozen custard, but it all depends on the flavour. Chocolate or coffee varieties will almost certainly contain some caffeine
Most breakfast cereals contain zero caffeine, though those that contain chocolate or cocoa tend to have small amounts.
A large Americano (around 473ml/16fl oz) contains around 225mg caffeine while the same size energy drink can have up to 357mg, which is edging very close to the 400mg recommended daily safe limit
There's unlikely to be any caffeine lurking in a packet of plain biscuits or an oatmeal and raisin cookie but choc-chip treats are another matter.