Do you really need eight glasses of water? How much should you drink?

How much water you should consume varies and might not align with the traditional eight glasses a day recommendation. According to a recent global study, factors such as environment, body size, composition, and energy expenditure play crucial roles in determining water needs. Athletes, for instance, may require up to 10 liters of water. The study utilized deuterium-based water, a traceable form with a heavy hydrogen isotope, to assess daily intake and loss.

The investigation discovered that water turnover peaks at around 4.1 liters per day for men aged 20-30 and approximately 3.1 liters per day for women aged 20-55. Individuals with higher body fat content have lower water requirements, as fat cells contain less water than muscles and organs. The study also noted an increased water turnover in women during the third trimester of pregnancy.

Dr. Rommel Tickoo, Director of Internal Medicine at Max Healthcare, emphasizes the absence of a one-size-fits-all formula. He suggests an average of three liters of water for adults but acknowledges the variability based on physical activity, climate, and other factors.

While dehydration results from insufficient water intake, excessive consumption can lead to hyponatremia, a condition characterized by low sodium levels in the blood due to water dilution. Symptoms include lethargy, water retention, and salt imbalance. Dr. RP Mathur, a senior nephrologist, warns that prolonged hyponatremia may be linked to cognitive issues, including dementia.

Dr. Mathur also highlights the dangers of low water consumption, such as dehydration and urinary tract infections. Individuals with kidney stones, urinary tract infections, or constipation should ensure adequate water intake. The elderly, whose thirst mechanisms may be impaired, must be vigilant about hydration.

The study considered not only environmental factors but also correlated water consumption with the Human Development Index (HDI). Lower HDI countries exhibited higher water turnover. Researchers from various countries collaborated on the study, analyzing 5,604 individuals across 26 countries, spanning from eight-day-old infants to 96-year-olds. The findings led to the development of an equation to predict individual water needs, aiming to address the lack of clean drinking water for 2.2 billion people.

Apart from the researchers’ equation, Dr. Tickoo offers a practical method to gauge sufficient water intake: if you urinate three to four times a day with clear urine, you’re likely hydrated. Darker urine signals the need to increase water intake.