No, it's not true. that we should all drink 2 liters of water per day. The ideal amount of water we have to ingest daily varies from person to person, according to weight, age, diet, room temperature and lifestyle.
Therefore, not all people need to drink 2 liters of water every day. For adults, the recommendation is 30 ml / kg / day.
Thus, an adult with 70 kg needs an average of 2.1 liters of water per day, while an adult of 50 kg, Need to 1.5 liter.
This quantity should be adjusted according to the needs of the individual and the environment. For example, if the person has a fever, if the day is hot, during and after exercise, after a very tempered meal, increase water intake.
To find out if the body needs water, simply follow the feeling thirsty. If you are thirsty, it is time to drink water and the body is giving the signal to avoid dehydration.
However, another way of knowing if the body needs water is to observe the color of urine. If it is colorless, like water, it is a sign that you are drinking the amount of water your body needs.
However, if the urine is strong yellow, it is because water is lacking and therefore you need ingest more fluids along the day.
For more information, talk to your GP or general practitioner.