It is important for health and well-being to keep the body sufficiently hydrated, notably by drinking plenty of liquids in the course of the day.
Dehydration happens when water loss is not compensated by water intake. It could happen because you are not drinking enough to meet the daily requirements of 1.5L and/or when you experience excessive fluid loss, due to intense physical activity, a very hot climate or illness involving fever or diarrhea.
Dehydration is a common problem. For example, surveys conducted in the UK, Germany and Italy show that sometimes children do not drink enough water, especially at school, as they depend on caregivers for access to fluids(1).
Through clinical trials on adults, scientists have identified that dehydration impacts physical(2) and mental(3) performance. Consequences of mild dehydration (a loss of 1-2% of body weight) include thirst, tiredness, headaches and a decrease in alertness, concentration and memory, as well as loss of endurance and sports skills.
Dehydration can be avoided by drinking the recommended daily amount of water. When you feel thirsty, dehydration has already set into a certain degree. So drink regularly throughout the day, even before you feel thirsty.
Hydration of young children
Infants have special water requirements, because:
- Their bodies contain relatively more water than adults’ bodies.
- They have a higher skin surface/body volume ratio.
- They excrete a more diluted urine, due to their immature kidneys.
- It is more difficult for them to communicate their thirst.
Hydration of the elderly and the sick
Elderly people should be especially aware of the importance of drinking enough water, mainly because the sensation of thirst diminishes with age, as does kidney function. Remember, too, that in certain cases the sick and the elderly may depend on others to drink.
Tips to prevent dehydration
- Don’t wait until you are thirsty to drink, you’re already dehydrated! A good habit is to sip water all along the day
- Keep in mind that some people depend on others to drink: babies, sick people and the elderly.
Other tips for hydration
Sources: (1) Fadda et al. Washington, DC. November 2008; (2) Shirreffs (2005). Nutr Revs. 63: S14-S21; (3) Ritz and Berrut (2005). Nutr Revs. 63: S6-S13