All your life it has been said that you have to drink two liters of water a day, especially when it is hot. But this recommendation lacks a scientific basis and healthcare professionals are less and less adventurous in prescribing specific amounts. One only has to consult the general recommendations of organizations such as the Institute of Medicine (IOM), the World Health Organization (WHO) or the European Food Safety Authority (EFSA) to understand how complex it is to determine how many glasses a day a person should drink. person: not even they agree.
This lack of consensus occurs because water requirements depend on many factors. “Intake needs are determined by age, sex or body weight. In addition, more water should be consumed in certain circumstances: physical activity, high environmental temperature, pregnancy and health problems (fever, vomiting and diarrhea)”, explains Montse Gavagnach, family doctor and director of the CAP of Valldoreix (Sant Cugat del Vallès), of Mútua Terrassa.
In the summer months, our hydration can be more affected because the body loses water through sweat. But the recommendation is the same. “Listen to yourself, because the body notifies you if you need an extra supply of water,” says Gavagnach. Some of the signs that warn us that we are dehydrated are excessive thirst, dry mouth, increased body temperature, urinating less than usual, difficulty concentrating, tiredness, fatigue, dizziness, confusion, ramps and tachycardia, among others.
To avoid these symptoms, it is advisable to always have a bottle of water on hand, “but we should not obsess over drinking a specific amount. If we are doing sports, we will surely drink more. On the contrary, if we find ourselves on the sofa at home with the air conditioning and we have eaten food rich in water, it will not be so necessary”, says Núria Mallén, dietician-nutritionist and spokesperson for CoDiNuCat.
Some people have a reduced ability to express thirst and must be offered water to hydrate. We are referring to specific groups, such as adults over 75 years of age, people with chronic illnesses or who are taking certain medications such as tranquilizers or antidepressants, children under four years of age, pregnant women, and people who perform intense physical activity or who work in hot environments.
However, experts warn against drinking excess water, because it also carries certain risks. “Ingesting amounts that are too high can cause hyponatremia, that is, an abnormally low concentration of sodium in the blood that in very serious cases can cause death,” explains Mallén.
Water should be the drink of choice and taken gradually throughout the day. “It is advisable to hydrate at breakfast, lunch, snack and dinner, but that does not mean that you have to neglect the rest of the time slots,” says Gavagnach, who adds that when we are doing physical activity in a hot environment it is advisable to hydrate every 20 minutes.
Doubts about whether drinking during meals can worsen digestion or cause weight gain is common. But there is nothing to fear. “Water makes the act of eating more pleasant, but we cannot overdo it either. We must bear in mind that the stomach has a limited capacity,” says Mallén. Whether it is hot or cold is not relevant either, but “having a cool drink generates more well-being”.
If water seems boring to us and that influences our daily intake, we can give it more flavor with a little lemon juice, mint leaves or citrus fruits and strawberries. Gavagnach points out that juices and infusions can also be an alternative, “but they should be taken in moderation and never as a substitute for water.” On the contrary, sugary drinks and alcohol dehydrate, so consuming them to quench our thirst can be counterproductive. “Alcohol is also harmful to health. There is no recommended intake,” warns Mallén.
It must be borne in mind that the body obtains 20-30% of its water through food. That is why it is important to add hydrating fruits and vegetables such as melon, watermelon, tomato, cucumber or lettuce to the diet. These ingredients can be part of salads or cold soups and, in the case of fruit, become an excellent snack.
Dehydration is one of the factors that can cause heat stroke, but the main causes are usually being exposed to a very hot environment or doing intense activities at high temperatures. Also, when the environment is very humid, sweat evaporates slowly and it costs more to reduce body temperature, says Gavagnach.
Indications that we are suffering from heat stroke are severe headache, nausea, dizziness, vomiting, flushed skin, increase in body temperature above 40°C, rapid heartbeat, altered mental status, confusion, irritability or loss of of consciousness.
To avoid this, experts recommend not exposing yourself to direct sunlight, wearing hats, walking in the shade, carrying water and drinking often, and not playing sports during the hottest hours. At home, we can lower blinds where the sun hits the most, use fans and air conditioning, and eat cold dishes.
If we also suffer from any of the symptoms described, we must call 911 and, meanwhile, avoid exposure to heat and cool off in a bathtub, with the hose, or with the help of a sponge. Fanning or putting cold, wet towels on the neck, armpits, and groin can also be helpful.
