The rules for proper hydration

Ensuring the daily need for water not only serves not to feel thirsty, but above all to keep intact the main functions of the body.

Water is considered the first drink in the world: nine out of ten people say they drink it every day, but almost one in three does not drink even a liter a day. These are the results of a survey conducted in 2017 in seven countries (China, France, Italy, Mexico, United Kingdom, United States and Turkey).

For proper hydration

Water is the main constituent of the human body. In adult males it represents about 60% of body weight, in females from 50 to 55% and in newborns as much as 75%.

In addition, water is involved in almost all functions of the human body. For this reason it is necessary to ensure the body the right hydration, especially when the loss of fluids is higher than normal, for example in case of increased sweating or when you are affected by excessive loss of stool (for example in case of gastroenteritis).

A body water loss of about 1% is normally compensated within 24 hours. However, the absence of such compensation and the further increase in body water loss have been shown to impair physical and cognitive functions.

Water and well-being

Water performs countless functions within the body: for example, it promotes the dissociation of electrolytes, allows metabolic transformations and numerous enzymatic reactions to take place and maintains normal body temperature.

In addition, it ensures the elasticity of the skin and a constant production of saliva and the tear film of the eyes, and allows the physiological processes of digestion to take place.

The urinary and cardiovascular tracts also benefit from water. In the first case because it increases diuresis, eliminates waste, prevents the formation of stones and performs anti-inflammatory and anti-infective actions. In the second, water is important because it reduces blood viscosity and therefore the risk of thrombosis.

Finally, water is essential for proper brain activity, because dehydration reduces brain efficiency and hinders cognitive processes.

When do you become dehydrated?

Body water is lost mainly through urine and faeces production and sweating. The first sign of dehydration, which already appears when the loss of water compared to body weight is only 2%, is thirst. However, it is better not to wait to be thirsty to drink, especially in the case of children and the elderly, who are more likely to experience dehydration as they have a lower perception of thirst and a lower natural stimulus to drink.

In case of mild dehydration, cramps, apathy, asthenia, increased irritability may appear; More severe forms induce general malaise, hallucinations, but in some cases you can also risk the onset of heat stroke.

A state of persistent dehydration is associated with a significant increase in the risk of many diseases, including serious ones, especially of the kidney.

At any age your dose

The need for fluids increases with age.

	Age range	Amount of liquids/day
Infants	0-6 months	100 mL/kg
	6-12 months	800-1000 ml
Children	1-3 years	1100-1300 ml
	4-8 years	1600 ml
	9-13 years	Male 2100 mL Female 1900 mL
Teenagers-adults	> 14 years	Males 2500 ml Females 2000 ml

The expected needs for adults must also be respected by the elderly, to whom great attention must be paid, because, as anticipated, they have altered mechanisms of thirst stimulus, which leads them to take less fluids than expected.

Expert advice

• Drink about 2 liters of water a day
• Better to drink more between meals to improve sodium disposal, intestinal and kidney function, but also brain activity
• You don’t have to wait for the feeling of thirst to drink, especially in summer
• Eat fresh seasonal fruits and vegetables every day
• Beware of alcohol and caffeine, which increase diuresis and therefore water losses
• Avoid sugary drinks: the metabolization of sugars requires the use of water and in the long run causes even more thirst.