It was popularized the rule that the advisable in terms of hydration would be to drink eight glasses of water per day. But is that so? Health experts clarify the issue and reveal what you need to know.
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05/08/2026
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Provatably you have heard that you should drink eight glasses of water a day in order to stay hydrated. However, this recommendation does not take into account several factors that impact the needs of your body. Health experts approached this subject in an article by Martha Stewart.
Why hydration is important
When it comes to health and well-being, staying hydrated is fundamental. “Water is essential for virtually all functions of the body,” says doctor Swapnil Patel. “Helps regulate temperature, transport nutrients, remove waste and keep joints and tissues lubricated”.
Water is also necessary for circulation and maintenance of volume and blood pressure, providing the structure of cells, promoting digestion and absorption of nutrients and assisting in brain function, including cognition and humor, according to nutritionist Giana DiMaria.
How much water do you need to drink a day?
After all, how much water should one drink a day? Patel notes that the National Academy of Medicine suggests 3.7 liters for men and 2.7 liters for women.
It should be noted that these recommendations include liquids from all sources, not just drinking water. This means that other drinks and foods that are consumed contribute to your fluid intake.
Where did the eight-drink rule come from?
The recommendation to drink eight glasses a day has been circulating for years. “This recommendation emerged at the U.S. Food and Nutrition Council in the 1940s, based on a medical intake of 2000 calories per day, estimated at 1 milliliter per calorie consumed,” says DiMaria.
“ The rule of eight cups a day comes from the recommendation to drink about 2.5 liters of water daily, but this includes the liquids of food, which is often ignored. Over time, it was simplified in rule 8×8, which consists of drinking eight glasses of 240 ml of water per day,” explains Patel.
However, there is no scientific evidence to support this average.
How to know if you're drinking enough water
According to DiMaria, these are the signs that indicate you're drinking enough water:
– Light yellow or pale urine;
– urinate regularly every three or four hours;
– stable energy levels;
– High elasticity of the skin;
Good digestion (e.g. no constipation or feces difficult to evacuate).
Tips for staying hydrated
If you have difficulty drinking water, note the following tips:
Set small goals: try to drink a certain amount at a specific time of day, which will gradually increase your intake;
Use a reusable water bottle: Keep close by during the day and take it with you when you leave. Those with straws are even better;
Make infusions: make water infusions with fruits and herbs such as lemon, strawberries and mint leaves;
Prioritise water-rich foods: moisturizing foods such as melons, grapes, peppers, tomatoes, cucumbers and soups can contribute to daily intake of liquids.