After every cup of coffee, a glass of water should be drunk, as coffee "drives", as often well-intentioned advice. But is it true that coffee removes water from the body and thus does not add to the fluid intake? No, so the answer of the DGE. It does not hurt to drink a glass of water with a cup of coffee, but it is not necessary. For many people, coffee makes a significant contribution to daily total water intake. It is included in the fluid balance - like any other drink, eg. A glass of juice, a cup of tea or a glass of beer in the evening.
It is true that caffeine contained in coffee has a diuretic effect. Both the amount of caffeine and the frequency of coffee consumption have an impact on this. However, the effect is only temporary and less pronounced with regular coffee consumption, so that the fluid balance is back in balance within one day.
At higher caffeine concentrations, the high intake of caffeine in addition to the increased water excretion also leads to an increased salt and especially sodium excretion. This effect is also regularly compensated by compensation mechanisms.
Because of its stimulating effect on heart and circulation coffee should not be used to quench your thirst, according to the recommendation of the DGE. Here are mineral and drinking water and other low-calorie drinks, such as spritzers of fruit juice and water and fruit and herbal teas the better alternative. However, there is nothing wrong with the moderate consumption of up to 4 cups of coffee per day with 350 mg of caffeine.
Does coffee remove water from the body?
With only a few cups of coffee, 24 hours are enough to compensate for the low diuretic effect of caffeine within 3 to 7 hours by counterregulation mechanisms. Coffee therefore influences the fluid balance in the medium term solely by the amount of water supplied with the beverage.
The recommendation to drink a glass of water with every cup of coffee was based on the a. on the misinterpretation of the results of a study in which the total amount of water was used as the sole measure for the assessment of the fluid supply:
For twelve volunteers who had not drunk coffee for five days, consuming six cups of coffee on the day of the experiment resulted in an average body weight reduction of 0.7 kg and a concomitant increase in urine volume and sodium excretion.
The conclusion of coffee as a liquid robber is based on a mistake that equated the temporary decrease in body weight and thus the total body water amount with a deterioration of the fluid supply. However, this decrease does not necessarily mean a deterioration of the fluid supply. A lack of water or fluid is characterized by factors such as an increase in the urine concentration (number of dissolved particles, osmolality) and increased elimination of electrolyte.
If coffee is regularly consumed in a constant amount, there is no increased excretion of water and sodium as a result of the increased activity of various compensation mechanisms.