Coffee's probably the most popular caffeinated drink, and an informal gathering with friends is often 'meeting for a coffee'. Whilst small doses of caffeine can help with alertness and energy levels, there can be negative side effects of excess caffeine intake: chest pain, dizziness, heart palpitations, insomnia, headaches, and some of us are more sensitive than others... (sadly I'm in the caffeine sensitive camp; I have been known to have the odd coffee to power me through an exam, but mostly I'm enjoying a decaf).
What's the safe limit? General advice is to stick to less than 300-400mg of caffeine a day (around 3-4 expresso shots). However if you're planning a pregnancy, then limit caffeine intake to around 200mg a day (around 3 cups or 2 mugs of instant coffee). Remember that green tea, black tea and cola contain caffeine too.
Have a look at the table below to compare the caffeine content of some of our favourite drinks.
(Australian Healthy Food Guide)