How Well Does Coffee Keep You Awake?

A cup of coffee can help keep you awake.
Image Credit: Alexander Spatari/Moment/GettyImages

Whether you're at the tail end of a long road trip, cramming for an exam or up late doing laundry when you'd rather be in bed, coffee can be a quick fix to get the job done. Although coffee can have its benefits, consuming caffeine in high amounts can have serious consequences too.



A cup of coffee can help keep you awake for several hours, but the caffeine will likely have its biggest impact within one hour of consumption.

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Choose the Right Amount

Drinking coffee can be part of a healthy diet, according to the Food and Drug Administration, however, it's important to know how much coffee you can drink without consequences. Factors to consider when drinking coffee include your body weight, the medications you take and your individual sensitivity to caffeine. Just one cup o' joe can give one person the jitters, while a couple of shots of espresso can leave another feeling just fine.

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One 8-ounce cup of brewed coffee contains about 96 milligrams of caffeine. The Food and Drug Administration advises that up to 400 milligrams of caffeine per day — the equivalent of four or five 8-ounce cups of most coffee — is safe for most adults. More than 400 milligrams of caffeine per day can cause health risks.

If you're pregnant, breastfeeding or have other health concerns, the FDA recommends speaking with your health care provider before consuming caffeine. However, those who don't already consume coffee and other caffeinated beverages, notes, are not encouraged to start.


Read more: Cold Brew Coffee

Caffeine’s Effects on the Body

Caffeine stimulates your nervous system, which gives you that energy boost and helps you feel awake. However, it can also increase your blood pressure and interfere with calcium absorption, according to the MedlinePlus. Too much caffeine can also cause heart rhythm disturbances and affect children's developing cardiovascular and nervous systems too.


When you drink a cup of coffee to keep you awake, the effect of the caffeine will likely peak within one hour. However, you may continue to feel the effect of the caffeine for four to six hours.

Don’t Make Your Coffee Unhealthy

A simple cup of black coffee has zero cholesterol and no sugar. Sadly, once you add dairy creamers, fancy flavorings and tasty toppings, your brew can become far more problematic than the harmless pick-me-upper you desire.


A medium iced latte made with nondairy milk is free from cholesterol and contains less than a gram of fat, whereas a medium iced latte made with dairy milk contains more than three times the amount of saturated fat as the nondairy latte and a whopping 19.2 grams of cholesterol.


If you add sugar, flavored syrups and whipped cream to your latte, expect to add on an extra pile of calories too. A medium frozen mocha with whipped cream contains over 58 grams of sugar—that's almost double the calories in a piece of chocolate sponge cake. If you're not careful, a simple coffee beverage can become a fat-filled, sugar-drenched dessert in a cup pretty fast.


Read more: This Heavenly Coconut Whipped Cream is Dairy-Free

To make your coffee beverage a bit healthier, use a cholesterol-free nondairy milk such as soy, almond, oat or coconut, ditch the extra toppings and avoid adding sugar. Or as Harvard Health Publishing suggests, you can skip the coffee altogether and opt for other healthier ways to keep you awake and energized such as working out, limiting alcohol consumption, staying hydrated and avoiding overly large meals.

Consuming several smaller meals and healthy snacks throughout the day, rather than three jumbo feasts, will also help keep you on your toes.




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