Water is one of the key components that is responsible for the origination of life on earth itself. Without it, life would simply cease to exist. Survival has depended to a tremendous extent on preventing dehydration dating as far back as when primitive organisms started moving into land from the oceans.
A major portion of the human body is composed of water. Even though an amount of water is produced in the body by metabolism and food ingestion, the body is not capable of producing enough water by itself.
Therefore it is vital to pay attention to the amount of water we drink daily to ensure that the water requirements of the body are met. If these requirements are not met, a number of negative health hazards may occur.
The human cells, tissues and organs owe a large percentage of their constituents to water. Without water, humans can only survive only a number of days. Even though the importance of water is well understood worldwide, it is almost always neglected in dietary recommendations and the significant importance of hydration often goes unmentioned.
This consequently leads to confusion among people and professionals in the nutrition and health fields as to whether drinking water on a regular basis is necessary and how much water should be consumed.
Without water, humans can only survive only a number of days.
We aim to address these issues and provide well researched and factually accurate data to clear these doubts and provide information on the amount of water required for the proper functioning of the body, how to identify dehydration and the ill effects of the condition and to highlight the importance of staying hydrated through this post.
What percentage of water is the body water?
In infants, 75% of body weight contributes to water and 55% of body weight in the elderly1. This is a tremendous amount. This water exists in the blood, muscles, brain and also in the bones. 92% of the blood accounts for water and 75% of the brain and muscles are water. Even the bones which may you may think does not contain water has roughly 22% water in them2.
Signs and symptoms of dehydration?
In a pediatric emergency department, one of the common incidents is the treatment of children with dehydration and accurately identifying whether a child is dehydrated is an important aspect in the treatment process.
A few symptoms and clinical signs have been established to identify dehydration and evaluate the condition. These symptoms include3:
- Thirst and dry mouth
- Not urinating in regular amounts and yellowish urine
- Dry and cool skin
- Headaches and muscle cramps
- Sunken eyes
- Sleepiness, confusion and weakness
A study was conducted among two hundred children to identify the accuracy of these clinical signs and their performance in identifying dehydration by experts in the Pediatric Clinic at the University Clinical Center of Kosovo. According to this study, the above mentioned clinical signs taken individually has a low sensitivity.
However, when taken as whole and under the evaluation of an expert, these signs can provide a significantly accurate analysis than previously thought. There are no diagnostic tools to identify dehydration and thus, clinical examination mentioned above is an acceptable method in medicine4,5,6.
What are the long-term effects of insufficient water intake?
Going for long periods without water has been identified to cause severe effects in the body. Lack of water can have a negative effect on cognition and proper brain function.
This is very important especially for young children, people living in hot climates and those who consistently exercise.
Insufficient water intake for long periods of time cause changes in cognitive function such as concentration, awareness and short term memory7,8 in addition to arithmetic ability, perceptual discrimination and psychomotor skills.
This is alarming when taken into consideration that more than 80% of Australians suffer from such symptoms and most of them are children9.
Another negative effect of insufficient water intake are headaches10. Neglecting water needs for extensive periods of time can have the long term effect of triggering migraine and can also prolong migraine11. However, it was observed in studies that ingesting water can provide relief to headaches induced by water deprivation within half an hour to three hours. Continuous deprivation may lead to permanent effects.
Blood volume is regulated by homeostatic processes in the body continuously to match water intake and output. Blood volume is a direct influencing factor to blood pressure and heart rate12. Insufficient water intake may cause long term effects and can cause unbalances in these systems.
Inadequate water consumption for significant periods is also identified as a main cause for constipation and can lead to difficulties in passing stool. Insufficient water for prolonged periods can also have a significant negative effect on the kidneys as well and contribute to kidney stones, kidney damage and hinder the functioning of the kidneys.
How much water should the average person consume daily?
Water is the only liquid nutrient that can hydrate the body. Therefore is extremely important to consume the necessary amount to avoid significant health hazards.
The body contains mechanisms to balance water and thus is compatible with a range of water intake. According to the European Journal of Clinical nutrition, a sedentary adult should drink around 1.5 litres of water per day13.
However, a huge number of factors influence water requirements such as ambient temperature and humidity, heat stress and also exercise.
Therefore the intake must be increased relative to such conditions since the above mentioned amount is determined only for standard conditions. Refer to the table below to get an idea about the required total water amounts from both food and water.
What food is good or bad for dehydration?
The recommended amounts of water intake does not have to come solely from drinking water. Certain types of food such as fruits and vegetables contain water and some contain a large percentage of water compared to others.
For example, cucumber, celery, tomatoes and radishes have more than 90% of its content in water.
In addition, fruits such as watermelon, strawberries, grape fruit and cantaloupe also contain large amounts of water. Fat-free skim milk, smoothies and sport drinks can also provide a large amount of the necessary water.
There exists various foods and beverages that can dehydrate you as well. Alcohol in particular can have a bad effect on hydration. It can cause cell shrinkage and make you excrete more water making you dehydrated.
Protein heavy diets can also induce dehydration as the nitrogen produced from the food requires more water to be filtered out. Herbal supplements may also induce more urination as found by a study in 2002.
The importance of staying hydrated?
Drinking the proper amount of water and staying hydrated is crucial to the body. It will ensure that the body functions properly. The body depends on proper hydration in order to carry out various functions such as carrying nutrition to cells, filtering harmful components, preventing constipation and maintaining proper functioning in the brain, heart and muscles.
Not having enough water can lead to numerous adverse health effects as mentioned above. Therefore it is of the utmost importance to stay hydrated.
If I do physical activity should I consume more?
When engaging in physical activity, the body excretes more fluid. During challenging physical activities, the body loses 6-10% of its body weight in the form of sweat. If the lost fluids have not been replenishes, dehydration will occur. This can result in reduced ability to perform, increased tiredness and decreased motivation14.
Therefore it is important to rehydrate during or after engaging in physical activities. When drinking according to thirst, the required amount of water may not enter the body since there is a deficit due to activity and more than normal amounts of water is required. Thus, more water should be consumed.
A final word about water
Water plays a vital role in the survival of human beings. It has many functions such as acting as carrier for nutrients, excreting waste products, acting as a shock absorber, a solvent and much more. To maintain a healthy life, proper amounts of water must be maintained in the body. This can avoid various health hazards such as cognitive decline, kidney stones, weakness and a range of other defects and disorders.
An approximate 1.5 litres of water should be consumed per day but more water might be needed depending on the environmental conditions and physical activity. Consuming the adequate amounts of water will ensure a healthy life free from unnecessary illnesses.
Adequate water intake amounts from both food and water
|Life stage group||Criterion||Adequate intake for males in l/daya||Adequate intake for females in l/daya|
|From foods||From beverages||Total waterb||From foods||From beverages||Total waterb|
|0–6 months||Average consumption of water from human milk||0||0.7||0.7||0||0.7||0.7|
|7–12 months||Average consumption of water from human milk and complementary foods||0.2||0.6||0.8||0.2||0.6||0.8|
|1–3 years||Median total water intake from NHANES III||0.4||0.9||1.3||0.4||0.9||1.3|
|4–8 years||Median total water intake from NHANES III||0.5||1.2||1.7||0.5||1.2||1.7|
|9–13 years||Median total water intake from NHANES III||0.6||1.8||2.4||0.5||1.6||2.1|
|14–18 years||Median total water intake from NHANES III||0.7||2.6||3.3||0.5||1.8||2.3|
|>19 years||Median total water intake from NHANES III||0.7||3.0||3.7||0.5||2.2||2.7|
|Pregnancy 14–50 years||Median total water intake from NHANES III||0.7||2.3||3.0|
|Lactation 14–50 years||Median total water intake from NHANES III||0.7||3.1||3.8|
Abbreviations: NHANES III, Third National Health and Nutrition Examination Survey.
a. The Adequate Intake is not equivalent to the recommended dietary allowances, RDA.
b. Total water represents drinking water, other beverages and water from food.
c. As noted above, these charts should only be used as a guideline for standard conditions, as a number of factors influence water requirements such as temperature, humidity, heat stress, physical activity, etc
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