How much caffeine should I really be having in a day?

Caffeine is a stimulant which is naturally found in coffee beans, cola nuts, tea leaves, and cocoa beans, and is usually consumed in the form of coffee, tea, energy drinks and sports supplements such as pre-workout powders. It has an effect on our central nervous system and can make us feel more alert and energized. Cue us leaping out of bed to make our morning brew!

Benefits of caffeine

Caffeine has been shown to enhance cognitive performance and can increase alertness, reaction time and memory. Hello snappy reflexes! It can also be beneficial for sports performance and can increase strength and muscular endurance.  

Caffeine has also been found to increase energy expenditure and is linked to a reduction in energy intake which may aid weight loss, so make sure you eat a proper meal to avoid running on fumes!  

Caffeine is also often used for pain relief, and can help treat migraines, which is why it is often included in OTC pain medications such as paracetamol.   

Recommended intakes of caffeine

The European food safety authority states that intakes up to 400mg (about 5.7mg/kg bw) consumed throughout the day do not raise safety concerns for healthy adults, and moderate chronic intakes up to this amount are not associated with adverse effects. The NHS recommends for pregnant women to consume no more than 200mg of caffeine a day due to negative effects caffeine can have on fetal development.  

There are substantial differences in response to caffeine ingestion. Some individuals may experience enhanced performance while others show no improvement. It is also possible to develop a tolerance to caffeine, which means its effects will be reduced unless a higher amount is consumed. Are you a 5 cup or decaf kind of person?

How much caffeine should I have to help with exercise performance?

There are many studies that show the benefits of consuming caffeine prior to exercise. Doses of 3mg/kg bw seems to be adequate for eliciting an ergogenic effect (fancy talk for enhancing energy production) when administered 60 minutes before exercise. It should be noted that these studies have been conducted on men and therefore the effective dosage may be different for women. Sorry ladies.

Commercial pre-workout powders generally contain 150-300mg of caffeine depending on the dosage, but this is generally within the range of 1.5-3mg/kg bw depending on the individual's body weight.  

Negative side effects of caffeine

There are moderate risks to caffeine consumption. Individuals with low caffeine tolerance may experience jitters, stomach upset, increased heart rate and an increase in anxiety when taking caffeine in high doses, so step away from the cafetiere my anxious friends! Caffeine intoxication can come as a result of excessive caffeine intake and can lead to symptoms such as restlessness, nervousness, sleep disturbances, GI issues, and heart palpitations. Well, we knew it couldn’t ALL be good didn’t we.. High intakes of caffeine over time can have adverse effects on cardiovascular health, calcium balance, bone density, behavior, cancer risk and male fertility. Shocking, right??

Is it possible to overdose on caffeine? 

Although rare, excessive intakes of caffeine can cause caffeine toxicity, with symptoms such as vomiting, hallucinations, convulsions and more. Although you won’t necessarily experience these symptoms from having an extra shot of espresso in your latte, you can still experience some negative side effects from excessive caffeine consumption as mentioned above. Some populations such as pregnant and lactating women, children and adolescents are particularly at risk of harmful effects of caffeine. There’s a reason coffee shops offer a babycino for the little ones, pretty sure they seem to have an endless supply of energy WITHOUT the help of our trusty cup of Joe. 

Caffeine and sleep

Caffeine is rapidly absorbed and reaches its peak value after 30-45 minutes, and its metabolic half-life can range from 2 to 10 hours. Some studies even suggest that it can take up to 20 hours for the effect of caffeine to wear off! Ever had a post-5pm coffee and then wondered why you had a restless night? As caffeine is a stimulant that may cause sleep disturbances, it may be useful to consider the half-life of caffeine and avoid having caffeinated drinks late in the day. 

What else should I consider when having caffeine?

It may be difficult to visualize how much caffeine is in popular caffeinated products, so here are a few examples of the typical caffeine content of different products:

• Cup of coffee 100mg 
• Shot of espresso 65mg 
• 50g dark chocolate <25mg 
• Cup of black tea with milk 50mg
• Cup of matcha green tea 70mg
• 250ml can of energy drink 80mg

A recent study by Which? found that the caffeine content in high street coffees varies drastically between different cafes, for instance a medium cappuccino from Costa contains 325mg caffeine which is 5 times the amount of a medium cappuccino from Starbucks at 66mg! I know, we were super shocked by this too! This goes to show how challenging it can be to estimate your caffeine intake and it is important to be mindful when choosing a caffeinated beverage. 

Conclusion

There will be a range of factors that affect the way we respond to caffeine and there is not one specific dosage that will be effective for everyone.  My advice would be to stay below the recommended amount of 400mg per day, if you have a low caffeine tolerance I would advise to have less or even no caffeine at all. If you drink coffee for the taste rather than the energy boost, try a decaffeinated version instead!  

We love our lattes! How do you take yours? Comment below (‘cause we’re nosey)