What happens in the body if we don’t drink enough water? Can fluids only be replenished by fluid intake, or are there other ways to reinject them? How does diet influence hydration? To answer these questions, we went to the consultation of the nutritionist Rocío Práxedes Gómez, from the Obesity Unit of Quirónsalud Valencia Hospitalwhich tells us about body water, foods that can interfere with hydration and other tips to avoid water retention.
The importance of water for the body
It is a vital component for the functioning of our body and represents about 60% of the body weight of an adult person. In concrete terms, two-thirds of the water is found in the intracellular space, that is to say inside the cells; and a third part is distributed among cells, organs and blood and lymphatic vessels.
Drink water, key to health
Water is essential to life, and for this reason the body is able to maintain a certain organic stability, even if there are significant variations on the outside.
In general, it is recommended drink 2.5 liters of water a day for men and 2 liters for women, according to the indications of the European Food Safety Authority, or EFSA for its acronym in English. It is also recommended that between 70 and 80% of daily hydration is obtained by fluid intakeespecially water, and the remaining percentage comes from food, especially fruits and vegetables.
How much water do you need to drink daily?
It is difficult to concretely establish the necessary daily liters, because the need for water depends on factors such as:
- The weight
- energy costs
- Environment temperature
- Physical activity
- The diet and its composition
- The presence of diarrhea, vomiting and fever
Is it possible to calculate it?
There are many methods for estimating water needs of each person according to their age, weight and caloric intake. But, in the case of obesity, this calculation by weight can be more complex, since in people with less lean mass only 45 to 55% of body weight correspond to water.
In any case, the most appropriate thing is to indicate the fluid estimates in a personalized way, especially in cases of heart, liver or kidney failure, or those with severe ongoing digestive losses.
How water is lost and replenished in the body
Each day our body loses water through breathing, sweat, perspiration, urine and feces. This must be replenished to maintain the fluid balance between ingested and spent fluid, which is obtained by drinking water and other fluids, consuming certain foods, and converting nutrients into energy, known as the name of oxidation or metabolic water.
In particular, the consumption of urine and water are the factors on which the water balance of the organism depends the most. Body water content remains constant in the kidneys, brain and gastrointestinal tract.
In addition, there are hormones such as adrenaline, cortisone and antidiuretics, among others, which help achieve fluid balance. And we must not forget thirst, which is the alarm signal of the hypothalamus to signal the need to drink water and avoid dehydration.
Food as a source of hydration
Food, especially fruits and vegetablesThey provide water to our body. To this we must add oxidation or metabolic water, which is what the body itself produces when it transforms fats, carbohydrates and proteins into energy. Thus, approximately 107 grams of water can be produced per 100 of fat consumed, 55 grams per 100 of carbohydrates and 41 grams per 100 of protein.
Be careful with these diets!
Diet composition can cause daily water requirements to vary. For instance:
- High protein diet. Eating too much protein and not drinking enough water can lead to dehydration.
- Diet high in sugar. People with high blood sugar who eat a diet high in sugars can also suffer from dehydration, as they can lose a lot of fluids through urine which eliminates excess glucose.
- Diet high in sodium. This can move water into the bloodstream and as a result blood volume and blood pressure can be increased.
What happens if there is not correct hydration
Water imbalance in the body can cause health problems, such as edema, dehydration, hypervolemia, hypovolemia and overhydration. There are several reasons for this, including diabetes, sweating, stress, gastrointestinal infections, kidney and heart failure. For this reason, it is advisable to go to the specialist to study each case and carry out the relevant tests.
Is there overhydration?
As for excessive fluid intake, although it may seem unbelievable, it can happen due to drinking more water than necessary, or due to other reasons such as stress, cirrhosis or heart failure, among others. This excessive hydration causes water intoxication, which leads to overloading of the kidneys and swelling of the cells, which in turn leads to pressure on the skull leading to severe headaches.
Weight changes: water retention or fat?
It is evident that fluctuations in body water can occur during the day, always at normal levels, due to the intake of liquids and food, sports practice, sweat and ‘urine. This is why it is advisable to interpret the changes in weight observed taking into account the losses and gains of body water in a day.
When faced with a very abrupt and drastic weight change, it is important not to confuse it with a loss or gain of body fat. Indeed, to lose a kilo of fat you have to restrict yourself to 7,000 kilocalories, which shows that real weight loss is not possible at once.
Tips for fighting water retention
The bottom line is:
- Follow a varied diet that includes at least 400 grams of fruits and vegetables per day
- Maintain good hydrationespecially in summer
- Prioritize drinking water compared to other drinks
- Consume less than 5 grams of salt per day
- Moderate packaged foods containing more than 1.2% sodium
All these guidelines help to maintain our health.