Guiding Your Career in Nutrition

Water bottle and water concept
Water bottle and water concept

Hydration: 5 Commonly Overlooked Benefits

9 minute read

We all know that water is the foundation of all life on earth and without it, humans, animals and all other life would cease to exist. Avoiding dehydration is, therefore, a primary survival priority for any living being. Drinking water, and enough of it for that matter, is also crucial for optimal health. After all, the human body is comprised of around 60% water, with organs such as the heart and brain, containing as much as 70% of their mass as water.

Consuming plenty of water and staying hydrated is something that is often overlooked by those looking to create a healthy lifestyle. It may be the seemingly mundane nature of stopping to take a drink of water that positions hydration fairly low on people’s daily list of priorities. In developed countries like the UK, perhaps we take for granted the fact that we have clean drinking water ‘on-tap’ and maybe this has caused us to underappreciate the many benefits of staying hydrated.

In this article, we’ll underline the importance of hydration and provide you with 5 overlooked benefits of drinking plenty of water. We’ll also provide some clarification on just how much water you should be drinking?

Pouring glass of water

How Much Water Should You Drink?

First and foremost, it is probably a good idea to determine how much water you should be drinking in the first place. It is here that the subject can become quite convoluted and contradictory, depending on where you are getting your information from.

Official World Health Organisation (WHO) reports [1] state “that it has been a challenge to establish a strict set of water consumption guidelines due to the varying factors which affect an individual’s needs”. For example, your activity status, your individual metabolic needs (caloric intake) and the environment in which you live, all affect your daily water needs. However, WHO suggests that 1-1.5ml per 1kcal intake is a benchmark for optimal water consumption for the average healthy person. This range is said to take into account a range of individual variables, like those mentioned above. For a man consuming 2,500 calories per day, he would need around 2.5 litres of water. For a woman eating the average 2,000 calories per day, she would require around 2 litres of water per day.

The British Dietetic Association (BDA) advise slightly differently than the WHO. The table below summarises the BDA’s recommendations [2], for a range of different populations.



Optimal fluid intake


0-6 months
7-12 months

550ml (milk)


1-2 years
2-3 years
4-8 years
9-13 years

14 years

Boys: 1680ml
Girls: 1520ml
As adults



Men: 2000ml 
Women: 1600ml

Pregnant women


+ 300ml per day

Lactating women


+ 600-700ml per day


Based on the data in the above table, male adults should aim to consume about 2,000ml of water per day, whereas women should consume around 1,600ml per day. Crudely, this equates to around 6-8 glasses of water each day, although this will clearly depend on the size of the glass. Most water guidelines base their recommendations on around 8, 8 fluid ounces of water (8 x 8 rule).

It’s worth noting also that the fluid recommendation doesn’t have to be plain water, and includes other dilute fluids that are consumed, like milk, low sugar cordial, tea and coffee. However, be mindful of the diuretic effect that caffeine can have, increasing your need to pass urine more frequently. This can be counter-intuitive when the goal is to remain hydrated. As previously stated, your daily need will increase depending on factors such as your daily activities and the environment. For example, a physically demanding job or exercising in hot conditions.

Working hard

5 Commonly Overlooked Benefits of Optimum Hydration

We all know that drinking plenty of water keeps us hydrated. When you’re dehydrated, you may develop a headache, become lethargic, aggravated and even feel nauseous. Your body will tell you when you’re becoming dehydrated via the thirst mechanism, although by the time you start to feel thirsty, the body is already well on the way to being dehydrated.

Your urine colour is a great indicator of your hydration status. When it is darker in colour, the body is dehydrated and you will likely go to the toilet less frequently because the body will attempt to preserve its already shrinking water reserve.

Outside of improved athletic performance, there are a host of other physical and mental benefits of staying hydrated, and many of these are often overlooked. Here are 5 commonly overlooked benefits of optimum hydration.

Helps to maintain optimal cognitive function

There are various studies that indicate how dehydration can negatively impact cognitive abilities. Particularly amongst children, drinking water and maintaining hydration, can help to improve visual attention [3]. In adults, it has been suggested that only a 1-2% loss of water in the body (mild dehydration) is enough to significantly impair concentration, critical thinking and even memory [4].

Brain power man

May support weight management

Increasing your daily intake of water has become a popular method for managing weight loss. One study found that consuming a large glass of water prior to a meal resulted in people reducing the amount of food that they subsequently consumed, which may aid those who are looking to lose weight [5]. In the study, it was reported that participants felt a reduced amount of hunger whilst maintaining an increased level of satiety when drinking 500ml of water before eating a meal.

Supports digestion and improves gut health

Constipation, amongst other things, is often associated with low fluid intake. Drinking sufficient water throughout the day can therefore help the gastrointestinal tract to move waste and pass stools with ease. One study involving elderly residents in a nursing home found that those residents that consumed the least amount of fluid, had twice the amount of constipation occurrences than those consuming the most [6]. It is especially important for elderly individuals to monitor their water intake, due to physiological changes in the body and age-related illnesses that can suppress the thirst sensation.

Helps to sustain healthy skin

As well as internal benefits on the body, drinking plenty of water can have dermatological benefits. Although increasing your water intake won’t stop you from ageing, it will help to maintain hydration of the skin [7] and consequently, the skin’s elasticity, thus reducing the likelihood of developing fine lines and wrinkles.

Healthy skin woman

May help to normalise blood pressure and blood circulation

Severe dehydration can lead to a rapid drop in blood pressure [8]. If persistently low blood pressure occurs, this can then deprive your body of oxygen because insufficient levels of blood are being pumped around by the heart. Drinking the recommended amount of water per day will contribute to a healthy blood pressure by maintaining your blood volume. In addition, with water being a major component of blood, water helps contribute to the transportation of essential vitamins, minerals and other nutrients around your body.

How Much Water is Too Much?

It is certainly possible to drink too much water. Consuming too much water is called water intoxication, or water poisoning, and it can be extremely dangerous. If you were to drink too much water, electrolytes in your blood, such as sodium, potassium and calcium, will be diluted, reducing their relative concentration. If sodium levels reduce dramatically, a condition known as ‘hyponatremia’, lethargy and confusion can start to occur. With more severe forms of hyponatremia, seizures, brain damage and even death may occur.

Amongst athletes, there have been many documented cases of over-consuming water whilst training or competing. Consequently, athletes have very quickly succumbed to water intoxication. Although this sounds a little scary, water intoxication is unlikely to happen by accident. The amount of water it actually takes to cause this level of damage is unclear, but ultimately, it would depend on the amount of water your kidneys are able to process in a given time frame. It is estimated that this figure is somewhere around 1 litre of water per hour, according to one report [9]. Based on this, it would be an unwise decision to drink several litres of water in just a couple of hours.


Drinking water is critical for many important bodily functions. Regularly drinking enough water has various health benefits and is often an underappreciated factor contributing to day-to-day wellbeing. Current guidance recommends that you drink around 2 litres to maintain optimal hydration levels, so keep a bottle at hand and stay hydrated!

Get ahead of the game with our range of nutrition courses. If you are keen to understand more about optimum nutrition strategies for performance, take a look at our Level 3 Sport and Exercise Nutrition Supplements Course. If you want to totally immerse yourself in the science of sports nutrition, why not consider our Level 4 Sport and Exercise Nutrition Coach qualification.


[1] Grandjean, A. (2004). Water Requirements, Impinging Factors and Recommended Intakes [online]. Available at: [Accessed 27th July 2021].

[2] The Association of UK Dieticians. Fluid (Water and drinks): Food fact sheet. Available from: [Accessed 27th July 2021].

[3] Edmonds, C. J. Jeffes, B (2009). Does having a drink help you think? -7-year-old children show improvements in cognitive performance from baseline to test after having a drink of water. Appetite, [online] Volume 53 (3). pp 469-472. Available at: [Accessed 26th July 2021].

[4] Riebl, S. K. Davy, B. M. The Hydration Equation: Update on Water Balance and Cognitive Performance (2013). ACSMs Health, [online] Volume 17 (6). pp 21-28. Available at: [Accessed 26th July 2021].

[5] Dennis, E. A. Dengo, A. L. Comber, D. L. Flack, K. D. Savla, J. Davy, K. P. Davy, B. M (2010) Water consumption increases weight loss during a hypocaloric diet intervention in middle-aged and older adults. Obesity. [online] Volume 18 (2). pp. 300-307. Available at: [Accessed 26th July 2021].

[6] Robson, K. M. Kiely, D. K. Lembo. T (2000). Development of constipation in nursing home residents. Diseases of the colon and rectum, [online] Volume 43 (7). pp. 940-3. Available at: [Accessed 26th July 2021].

[7] Palma, L. Marques, L. T. Bujan, J. Rodrigues, L. M (2015). Dietary water affects human skin hydration and biomechanics. Clinical, Cosmetic and Investigational Dermatology [online]. 8. pp 413-421. Available at: [Accessed 27th July 2021].

[8] Watso, J. C. Farquhar, W. B (2019). Hydration Status and Cardiovascular Function. Nutrients [online]. Volume 11 (8). pp. 1866. Available at: [Accessed 27th July 2021].

[9] Choi, H. Y. Park, H. C. Ha, S. K. (2015). High Water Intake and Progression of Chronic Kidney Diseases. Electrolytes & Blood Pressure [online]. Volume 13 (2). pp 46-51. Available at: [Accessed 27th July 2021].

Popkin, B. M. D’Anci, K. E. Rosenberg, I. H (2010). Water, hydration and health. Nutrition reviews [online]. Volume 68 (8). pp 439-458. Available at: [Accessed 27th July 2021]


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