Coffee is part of daily life for many Australians. Tea, cola, energy drinks and chocolate add a little more caffeine to the day. Most people never think about how much it all adds up to. Knowing the rough numbers makes it easier to enjoy your coffee and still sleep well.
This post covers how much caffeine is in common drinks and what the health guidance says. It also looks at who should take more care. You will find some simple ways to cut back if you feel you are having too much.
What caffeine does in the body
Caffeine is a mild stimulant found naturally in coffee, tea and cocoa. It is also added to cola and energy drinks. According to healthdirect, its effects usually start about 30 minutes after you have it. They can last up to six hours, depending on the person.
Caffeine also stays active for longer in some groups. Healthdirect notes this includes babies and people who are pregnant, and that older people can be more sensitive to it. That helps explain why the same cup of coffee can feel very different from one person to the next. It is also why a late afternoon coffee can still be working at bedtime.
How much caffeine is in common drinks
The amount varies a lot between drinks and brands. Healthdirect gives these rough figures as a guide. A 50 mL espresso has about 145 mg and a teaspoon of instant coffee has about 80 mg. A 250 mL energy drink also has about 80 mg.
Tea and soft drinks are lower. A 220 mL cup of black tea has about 50 mg and a 375 mL can of cola has about 36 mg. A 50 g bar of milk chocolate has about 10 mg. Cocoa contains caffeine naturally, so the treats in our post on raw cacao and coconut oil still add to your daily total.
Food Standards Australia New Zealand also sets rules for some products. Cola type drinks must not go over 145 mg of caffeine per kg of drink. Energy drinks can have no more than 320 mg per litre. Their labels must say they are not suitable for young children, pregnant or breastfeeding women or people sensitive to caffeine.
How much is too much for adults
For healthy adults, healthdirect caffeine guidance says about 400 mg a day is safe. That is roughly 2 espressos, 4 instant coffees or 8 cups of black tea. It is a general guide rather than a target. Some people feel jittery on much less.
Regular heavy use is a different story. Healthdirect says more than 600 mg a day can cause insomnia, heartburn and stomach ulcers. It can also contribute to anxiety and depression and to bone loss in women after menopause. Caffeine can raise blood pressure, so people with high blood pressure may want to have less.
Food Standards Australia New Zealand explains that there is no formal health based limit, such as an Acceptable Daily Intake, for caffeine. That is why the advice is framed as a sensible amount. If you are not sure what suits you, your GP is the best person to ask. This is especially so if you take medicines or have a heart condition.
Pregnancy, breastfeeding and children
Caffeine can pass to a baby through the placenta. Healthdirect notes that caffeine in pregnancy has been linked to a higher risk of miscarriage, stillbirth and low birth weight. The suggested limit during pregnancy is 200 mg a day. That is about 1 espresso, 2 instant coffees or 4 cups of tea.
Pregnancy, Birth and Baby gives the same 200 mg daily limit for breastfeeding. It notes that caffeine passes into breast milk and can make a baby wakeful and irritable. Energy drinks are labelled as not suitable during pregnancy or breastfeeding. A midwife or doctor can talk through what is right for you.
Children need much less. Healthdirect says people under 18 should have less than 2.5 mg per kg of body weight each day. For a 40 kg child that works out to about 120 mg. Children who drink energy drinks may also have sleep problems and bed wetting.
Caffeine and sleep
Poor sleep is one of the most common signs of too much caffeine. Because the effects can last for hours, timing matters as much as the amount. Having your last caffeinated drink earlier in the day gives it time to wear off before bed. Our post on getting a good night’s sleep has more ideas for winding down at night.
It can become a cycle. A poor night leads to extra coffee the next day, which then makes the next night worse. Breaking that pattern often starts with moving your last coffee earlier. Water, herbal tea or a short walk can fill the gap in the afternoon.
Cutting back without the headaches
Stopping suddenly can bring on withdrawal. Healthdirect says symptoms usually start within a day and can last up to a week. They include headaches, tiredness, irritability, nausea and trouble concentrating. People who have had a very large intake may feel them for longer.
A slow approach is usually easier on the body. Healthdirect suggests cutting down over time rather than stopping all at once. Healthdirect suggests these simple changes:
- drink one less caffeinated drink each day
- swap some of your coffees for decaf
- brew tea for less time or choose herbal tea
- pick caffeine free soft drinks or plain water
- check ingredient lists for caffeine and guarana
Movement can help with that afternoon slump as well. If you sit at a desk all day, try a few of the stretches for people who sit at an office desk instead of reaching for another coffee. Getting out with friends is good for your mood too, as our post on the mental health benefits of playing games explains. Small changes like these add up over a week.
Frequently asked questions
Can decaf coffee help me cut back?
Yes. Healthdirect lists switching some coffees to decaf as one way to cut back. Check the label if you need to keep your intake very low.
Are caffeine powders allowed in Australia?
Some are not. Food Standards Australia New Zealand says some caffeine products are not considered safe and have been banned in Australia and New Zealand. These are usually sold as sports supplements in the form of powders and syrups.
Does guarana contain caffeine?
Yes. Guarana is a plant that is naturally high in caffeine. FSANZ requires foods containing guarana to be labelled as containing caffeine.
How long does caffeine last?
Healthdirect says the effects start after about 30 minutes. They can last up to six hours. Caffeine stays active for longer in babies and during pregnancy.
This article is general information only and is not medical advice. Please speak with your doctor or a qualified health professional about your own health and caffeine intake.