Hydration – How Much Is Enough?


Every week, I chat to the lovely gang at iRadio about a different health topic, and recently we discussed the importance of hydration. I thought it was great idea to discuss this given that we’re peak summer right now, with (hopefully!) warmer weather and many people head abroad on holidays during this time too. The iRadio gang asked me some really concise focused questions on the topic, so I decided to use those as a blueprint to share our discussion with you! Let’s get into it.

First of all – What IS hydration?

A simple definition of hydration in a health sense is the act of taking in water. Water is essential for life – it takes up the largest proportion of our bodies, ranging from 75% bodyweight in infants to 55% in the elderly. As you can see, this proportion declines with age. Water takes up slightly more of a percentage in males than females as females have a higher body fat per cent. We take in water to remain in a state of adequate hydration – i.e. preventing dehydration, and maintaining adequate hydration is crucial to our short and long term health.

Okay then – so how important is it to stay hydrated?

A one-word answer – VERY! Water, as the main constituent of our bodies, has so many important functions. These include:

  • Body temperature regulation – for example, sweating is a really effective way for us to reduce our body temperature
  • The transportation of nutrients and compounds in our blood
  • Removal of waste from our bodies via the formation and passage of urine
  • Acting as a lubricant and shock absorber in our joint

So as you can see, it’s a continuous cycle as we move through the different activities of our day, hence why we have to keep on top of maintaining optimal fluid intake! Examples of health issues that are prevented by adequate hydration include; for the prevention of constipation, kidney stones and urinary tract infections, and good kidney function in the long-term.


How much water is recommended to stay hydrated?

As with most things health-related – it depends! It depends according to age, gender, activity levels, medical history in particular. For example, as you’d expect, as we grow, we need to take in more fluid as our bodies get bigger. Another example is how pregnant and lactating women need more – they’re providing fluid for two or more people! The British Dietetic Association has a fantastic ‘fluid’ fact sheet with age range-based recommendations for optimal daily intakes of water through drinks (outside of activity) (link to that here). They estimate drinks provide 70-80% of our water needs, while the remaining 20-30% comes from certain food (e.g. soups, stews, some fruits, veg, yoghurts)

Irish dietary guidelines updated in 2016 recommend water as the first choice of fluid, as it hydrates us without adding extra calories or stimulants such as caffeine. In terms of specific volumes for certain age groups:

  • For children aged 5-8, 1.6L of fluid per day is advised.
  • For children aged 9-13, girls are advised to take in 1.9L and boys 2.1L
  • For children older than that and adults – 2L a day for females is advised, and 2.5L a day for males

An important point to note is that water and milk are the recommended best drinks for dental health. Diet drinks are sugar-free but their acidity can damage teeth. And remember, water lost through sweat when exercising needs to be replaced on top of those recommendations to maintain performance and health – this is also true when we are in warmer climates or seasons (as is the case currently!)


Is it possible to drink too much water?

Technically, yes, but it’s very rare. Over-hydration can occur as a result of excessive water intake relative to needs, or (due to certain medical conditions) inappropriate retention of water in the body. If we just look at excessive intake – if the body can’t get rid of the fluid taken in quickly enough, this can cause fluid imbalance in the body and because of too much water, sodium, or salt levels in the blood can become too low, which can be very very serious – this is called hyponatremia, and can make a person feel sick, cause them to vomit, make them very confused and pose a significant risk to our neurological status, and life if very severe.

Drinking too much water has been seen more so among major endurance athletes hydrating before and after big events, not so much the general population – these athletes lose salt through their sweat too which compounds the problem. This is a whole other topic and one I’m not an expert on, so suffice it to say – than you CAN drink too much water, but for the general healthy population, sticking to the guidelines above will steer you right. If you have a medical condition and have to manage your fluid balance (which can be the case for example with certain heart, kidney conditions, among others) then it’s a different story and should be discussed with your doctor to know the daily intake you need to aim for. But overall, dehydration is far far more common, particularly as we age.


How do you know when you’re hydrated?

The colour of urine is the best indicator; if you are drinking enough your urine should be a straw or pale yellow colour. It’s really important to note that thirst is a sign that a person is already dehydrated. Thirst is only part of the way we regulate hydration in the body. When you drink you stop you feeling thirsty before your body is completely rehydrated. The best way to stay hydrated is to drink water steadily throughout the day. Even a very small amount of dehydration can lead to negative effects on mental and physical function and these become more severe as dehydration gets worse.

Symptoms and signs of DE-hydration to look out for include, for mild dehydration; a dry mouth and/or lips, headaches, feeling light-headed or dizzy, feeling tired and poor concentration – many of us familiar with those! When the body detects that more water is needed the first thing that happens is that the kidneys reduce the amount of water lost in the urine. This means that the colour of the urine becomes darker, and can smell stronger – so as we’ve said, the colour of your urine is your indicator! Another urine indicator is how often you’ve gone to the bathroom – if you notice that’s a lot less than your usual on a given day, it’s a good sign you might need to drink that water up.

Remember – dehydration can happen more easily if:

  • You’ve been exercising
  • You’ve been out in hot climates or weather
  • You have a history of diabetes
  • You have consumed alcohol, as it’s a diuretic, meaning that it makes you urinate more frequently – this is also true of caffeinated drinks, and some medications
  • You have a high temperature e.g. if unwell
  • You have had a gastro-intestinal illness causing vomiting or diarrhoea resulting in fluid loss

Finally, it’s important finally to remember that elderly persons in particular may not be as in tune to that sense of thirst or their ability to get fluid themselves or ask for it may be compromised, but they really need to stay hydrated as they’re at a greater risk of urinary tract infections and falls especially – really important to remember for your family members, friends and/or persons you care for as we head into warmer months.

And that’s a wrap gang! I really hope you found this article helpful and informative – leave a comment or find me on Instagram/Twitter/Facebook @theirishbalance!

Ciara 🙂 x

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