Healthy Adults Should Aim to Consume 1.5 Liters of Water Daily, Warns Cardiorenal Physiologist

Most people drink when they’re thirsty, but knowing whether to consume a two-liter bottle per day can be challenging. However, a healthy adult doesn’t need to worry about dehydration, says Mattias Carlström, a professor in cardiorenal physiology at the Karolinska Institute. He recommends consuming approximately one and a half liters per day, but if you are more physically active or sweat more, you may need more. When engaging in sports, you can lose up to six to ten liters of water and may need to drink significantly more than the normal intake.

Drinking too much, too fast can be life-threatening. Consuming around five liters of water in less than half an hour can cause serious damage, potentially leading to a condition known as water poisoning. This occurs when the concentration of salts in the body becomes too low, causing water to move into the brain. The brain may swell, potentially leading to seizures, headaches, and loss of consciousness.

On the other hand, drinking too little water can also have similar symptoms. It can lead to problems with concentration, headaches, and irritability.

As for the type of liquid to consume, tap water is usually the best choice, unless you are engaged in physical activity. In that case, it might be helpful to add a bit of salt or sugar. Consuming coffee or beer, which are diuretics, can actually lead to a loss of fluids.