We can go 50 days without food, but only two or three days without water. Water is essential for the human body and we need about 2.5 liters of water a day.1 Most of this comes from liquids, but some comes from solid or liquid foods.
A total of 2.5 liters per day is a rough estimate and depends on several factors:
Age
sex
weight
height
Level of physical activity
Temperature and climate
Water in our body
The water content of our body decreases with age. Newborns have the highest 75% and the elderly the lowest 55%. Adults have an average of 60% water in their body.1,2
Where is water stored in the body? One third is in our blood and between our cells, while the majority, two thirds, is inside our cells.
When your body becomes dehydrated, it can affect many body functions because water regulates:2
Body temperature
Hormonal regulation
Stimulation of energy expenditure
Blood thickness
Skin moisture
Cellular longevity
Positive digestion
Cushion function of spinal cord, brain and eyes
Disposal of residues
Our bodies are constantly losing water through breathing, sweat, urine and feces.1 We lose even more water when we are sick with vomiting and diarrhea, increasing the risk of dehydration.
How thirsty are you? Because water is so important to our survival, our bodies have a very good way of letting us know when we are dehydrated. thirst When you feel thirsty, you know you need to drink.
Have you ever wondered how your body knows when you are dehydrated? In our brain, receptors measure the composition of the blood and react when it thins. As a result, a hormone called vasopressin is released into our body. Vasopressin ensures that we retain more water in our body by keeping water in the kidneys and making us feel thirsty.
urine and hydration status
If you want to check your fluid levels, an easy way is to look at the color of your urine. Light yellow means you are hydrated, but when it turns dark yellow, you are dehydrated.
Dehydration, which occurs when the body does not have enough water, is very dangerous. If we lose just 1% of our body water, we have less energy to exercise, control our body temperature and lose our appetite. At 5% water loss, our mental performance drops; difficulty concentrating, irritability, sleepiness and frequent headaches. If we lose more than 8% of our water, we can actually die.1
Have you ever been so focused or busy that you simply forgot to drink? Symptoms that can occur are: 1
Dry, sticky mouth
Muscle cramps
Headache
Dry skin
Fatigue
Loss of concentration
Stay hydrated
The European Food Safety Authority (EFSA) offers the following guidelines for healthy general water consumption.