Less Coffee, More Water How Much Water to Compensate for your Coffee Dependency?


Mei Lin Valencia, MPH

This means that for every cup of coffee or two cups of black tea, you should drink one cup of water to make up for the diuretic effect.



If you consume more than 200 to 300 milligrams of caffeine daily – the amount in two to four cups of coffee – you are at risk for a variety of side effects

Total Body Water and Body Mass


It can take up to 10 hours for caffeine to completely clear your system (Evans, Richards et al. 2020).


Caffeine has been identified as a psychoactive substance that can alter mood and behaviour. Caffeine in its pure form is a dry, bitter taste powder, and is known medically as trimethylxanthine. But is coffee actually dehydrating? And if so, how much water do we need to drink to compensate the coffee we intake? How much water to compensate for your coffee dependency?


To be able to collect 25 participants for a 14 day trial of consuming 4 cups of (200ml) of coffee per day or water for 3 days (Pre and Post test) as a Randomised Controlled Trial (RCT) cross over design of study and to determine the participants; (BMI), (24 Hr. urine) and (Haematological hydration markers).


To determine whether caffeine count toward hydration To determine if caffeine can be a diuretic To determine whether water can flush out caffeine in the body


No Evidence of Dehydration with Moderate Daily Coffee Intake: A Counterbalanced Cross-Over Study in a Free-Living Population (Killer, Blannin et al. 2014). The effects of coffee consumption were compared against water ingestion during 3 consecutive days. Physical activity was controlled, food and fluid intake was controlled and participants consumed either 4×200 mL of coffee containing 4 mg/kg caffeine or the same amount of water

  • Water and other beverages can be a healthy substitute for coffee or sodas and help cut down your daily caffeine intake. The U.S. Institute of Medicine recommends that adult men consume 3 liters of water daily; Women should consume 2.2 liters. If you are not drinking enough water, try increasing the amount you drink by a glass per day, around 8 ounces each, until you reach the recommended consumption. (Dong, Li, Sun, Li, & Zhang, 2020; Zhou et al., 2018)
  • You can see a diuretic impact if you have more than four cups of coffee a day, but if you take fewer, then you’ll be OK in a dehydration situation.
  • Coffee has equal hydrating characteristics to water when drunk in moderation.


  • Killer, S. C., Blannin, A. K., & Jeukendrup, A. E. (2014). No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS One, 9(1), e84154.
  • EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA). (2015). Scientific Opinion on the safety of caffeine. EFSA Journal, 13(5), 4102.
  • Dong, X., Li, S., Sun, J., Li, Y., & Zhang, D. (2020). Association of Coffee, Decaffeinated Coffee and Caffeine Intake from Coffee with Cognitive Performance in Older Adults: National Health and Nutrition Examination Survey (NHANES) 2011–2014. Nutrients, 12(3), 840.
  • Zhou, A., Taylor, A. E., Karhunen, V., Zhan, Y., Rovio, S. P., Lahti, J., . . . Hyppönen, E. (2018). Habitual coffee consumption and cognitive function: a Mendelian randomization meta-analysis in up to 415,530 participants. Scientific Reports, 8(1), 7526. doi:10.1038/s41598-018-25919-2