Coffee is one of the most popular stimulants around the world - Kiwis consume their fair share and we generally like it strong.

Figures show that the average NZ cafe coffee is often made with more than twice the amount used in the UK. So while four cups of freshly brewed coffee is considered moderate consumption in England, it may only take Kiwis three cups to get to the 400mg level of caffeine a day that is considered safe.

Caffeine blocks adenosine - a chemical that makes you naturally drowsy - thus increasing your concentration and reaction speed. By drinking coffee regularly, people tend to get addicted to its stimulating and mood altering properties.

Moderate coffee intake is generally harmless and, in fact, there are several health benefits associated with drinking it. But excessive consumption can lead to side effects such nervousness, anxiety, muscle twitching and irregular heartbeats.