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Fluid balance
Questions patients ask
Q. Does coffee count towards my daily fluid intake?
A. Yes. Experts have stated that drinking a variety of caffeinated beverages, including coffee, can contribute to meeting your body’s daily requirement for fluids1. Black coffee contains more than 95% water.
Q. What is a diuretic?
A. A diuretic is a substance that increases the amount of fluid lost from the body, which can eventually lead to dehydration. It does so by substantially increasing the amount of urine produced by the kidneys.
Q. Is coffee a diuretic?
A. The caffeine in coffee has a mild, short-term diuretic effect, however this doesn’t counterbalance the fluid intake from coffee drinking. Moderate consumption of coffee has a similar effect on the body’s fluid loss as urine, as water2. Decaffeinated coffee contains minimal amounts of caffeine and will therefore have the same effect as water.
Q. Is it true that drinking coffee will make me dehydrated?
A. Recent research shows that moderate coffee, and caffeine, consumption does not lead to dehydration3.
Q. Will drinking coffee make me urinate more?
A. While caffeine may have a mild, short-term diuretic effect in people who do not normally consume caffeinated drinks, such as coffee, studies have shown that this is not the case for people who regularly consume caffeinated beverages4.
Q. If I drink coffee before exercising, will I become dehydrated?
A. No. Recent research shows that moderate consumption of caffeine does not increase the risk of dehydration during exercise5. On the contrary, it is important to drink sufficient amounts before exercising, and caffeinated beverages can contribute to meeting fluid requirements1.
Q. Do I need to drink less coffee during the summer, or in hot weather?
A. No. There is no evidence that caffeine causes dehydration, or negatively affects temperature control, in a hot environment6. Experts have stated that drinking a variety of caffeinated beverages, including coffee, can contribute to meeting your body’s daily requirement for fluids1.
This information is intended for healthcare and professional audiences.
