Caffeine - how much is too much?

As a nervous system stimulant, caffeine makes us feel more alert. Some caffeine is fine yet too much can affect how we feel. People’s sensitivity to caffeine can vary so that is something to be mindful of. If you feel anxious or jittery on the caffeine amounts you currently consume, consider reducing it.

Too much caffeine can REALLY interfere with the QUALITY of sleep you get. If there’s caffeine in your system, it blocks your body’s ability to go into deep sleep – where the real restoration happens. Caffeine may be helping you during the day, but ultimately compromising your sleep QUALITY as it can make you wake up more often and leave you feeling less rested with a lower mood overall (and in need of more caffeine - it is easy to see how this creates a vicious cycle).


How much caffeine is ok?

The current recommendations are not more than 400mg per day for adults, 200mg per day for pregnant/breastfeeding women. There is roughly 100mg in a single shot (varies hugely depending on the blend/brew etc) but overall aiming for no more than 3 single shots/day is a good guide.

How much caffeine is in a single serving?

Remember too much caffeine can increase anxiety, this is very important for kids/teenagers who might be having caffeinated drinks. It’s suggested to limit to less than 3mg/kg, so for a 40kg child that’s less than 120mg. Enter the problem with energy drinks! They vary but a 250ml can of V for example contains 80mg - the big cans, far more.

Quick facts:

  • Caffeine has a half-life of six hours. 12 hours after consumption, there's still a quarter of the caffeine in your system. Meaning if you have a coffee at 7am, at 7pm there is still roughly ¼ of the caffeine in your system.

  • Caffeine blocks the tiredness receptors in your brain, meaning you tend to crash once the caffeine has worn off – leaving you feeling worse for wear and wanting more caffeine.

  • It's best to limit your overall caffeine consumption and have it as early in the day as possible.  

  • Try decaf in the afternoon, although do be mindful, decaf coffee does not mean caffeine-free. Decaf can still have between 15-30% of the caffeine in a normal coffee, so if you have lots, it can still add up. 

  • Herbal teas can be a good option, but be sure any teas you have in the afternoon are not black tea based, or you have the same issue. Rooibos, otherwise known as Red Bush, is a caffeine-free tea worth trying.



Check out my video which covers a bit more detail about:

  • How caffeine affects your body

  • How many cuppas is ok

  • The impact of caffeine on your sleep

  • What time to have caffeine


A few Breakfast TV interviews you might find interesting too:


Download our FREE resource How much caffeine are you having?

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Published By

Claire Turnbull



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