NUTRITION | CAFFEINE
Healthy from the Start Resources for Shiftworkers
Caffeine is found in a wide variety of foods, drinks, and supplements, and can be used as a great fatigue management tool for shiftworkers. Most people feel the effects of caffeine after consuming 100-200mg (equivalent to a medium sized coffee or small energy drink), but some people are more impacted by caffeine than others. The effects of caffeine last much longer than many people realise, so it’s important to limit your consumption to no more than 400mg per day.
Caffeine is a very popular fatigue management tool used by shiftworkers, and can be found in foods, drinks, and supplements. Some of the most common sources of caffeine include (34):
Caffeine is both a mental and physical stimulant, meaning it can impact your performance, fatigue, and sleep. Caffeine helps to improve alertness and mood, with effects peaking within 30-70 minutes of consumption, but it stays in your system for many hours after the effects wear off, sometimes for up to 7 hours! This is important to keep in mind when consuming caffeine in the hours before sleep. Read more about managing the impacts of caffeine on sleep here.
In Australia, it is recommended that adults consume no more than 400mg of caffeine per day, however, 400mg of caffeine can look different depending on how you consume it. Some ways to reach this day limit include: 2-3 cups of coffee (made with espresso), 2-3 cans of energy drinks, or 5-6 cups of black tea.
Just because 400mg is the upper limit doesn’t mean that you have to consume this much to feel the alerting effects of caffeine. You only need to consume 100-200mg of caffeine to experience the beneficial effects (34-37).
Some things to keep in mind when using caffeine as a fatigue management tool for shiftwork (34-37):
• Everyone is different, and some people feel the effects of caffeine more than others. Adjust your caffeine consumption to your individual needs, and watch out for signs of overconsumption – a racing heart, shakiness, headaches, dizziness, restlessness and irritability.
• If you are not a regular consumer of caffeine and plan to start using it for fatigue management, it’s a good idea to start small and increase gradually over time.
• Caffeine can be diuretic, which means it increases the rate at which you produce urine. This could leave you needing to use the bathroom more than you otherwise would. For some shiftwork jobs, using the bathroom frequently isn’t always an option.
• Caffeine is a stimulant and acts like a drug in your body. Over time, you can build up a tolerance to it, meaning that you need more to feel the same effects. You can also develop a dependency, where you will experience withdrawal symptoms when you don’t consume it. Try to use caffeine for fatigue management only when you really need it, rather than consuming caffeine out of habit.
• Very high caffeine content substances (e.g., pure caffeine powder) have been banned in many countries, including Australia, as they can cause serious health problems. Some of these substances can contain the same amount of caffeine as 50 cups of coffee!