Dehydration Nation

How to stay hydrated

As we start to see the first sunny days of the year, hydration and how to stay hydrated seems to be the (hot) topic of the moment. I have written about hydration before, but I have been asked no less than 8 times over the last week to provide comments for the press about how to keep properly hydrated so perhaps it’s time for another blog…

Water is essential for life. The body is roughly two-thirds water and this fluid performs many functions including the transport of nutrients, maintaining blood volume, removing waste products via urine and aiding movement of waste through the bowel, as well as acting as a lubricant and shock absorber in joints. It also regulates the body’s temperature. Drinking enough is vital to maintain good health in the short and long term, for example, for the prevention of constipation, kidney stones and urinary tract infections. Good hydration can also prevent other conditions such as chronic renal disease.

Dehydration is what happens when you don’t replenish the fluids lost through urine, sweat and breathing. The most obvious symptom is thirst but it’s not the only one or even necessarily the first one. A headache, a lack of concentration, lethargy or mood swings are not commonly recognised as marks of dehydration but they are all signs of a lack of fluid. Both fine and gross motor skills are also affected and although you may not necessarily notice impairment in your own motor skills (unless you are trying to thread a needle for example!) this is extremely pertinent in kids. A child that can’t concentrate for long periods, falls over a lot, over-reacts to your simple requests etc. might sound like just normal childhood behaviour, but a 2012 study found that 60% of school children arrived at school without being properly hydrated. Even mild dehydration has been shown to have an affect on cognition.

So what drinks are good for rehydration? Water and anything that contains it will generally rehydrate so if your child (or you) refuses to drink water but will happily drink squash – particularly if it’s a no-added-sugar one – juice diluted with water to reduce the sugar content, and milk that is fine. Tea and coffee also count and fizzy drinks but do think about sugar content and remember that caffeine is not recommended for children.

So how much is enough? The European Food Safety Authority (EFSA) recommendation for adequate intakes of fluid, per day is 2L for women and 2.5L for men. There is a chart below for recommendations for children too. There are all sorts of things that affect hydration level though. For example, sweating is a mechanism to cool the body down so if you sweat a lot you will be losing a significant amount of fluid, which will need to be replaced.

Short of measuring the amount you or your child drinks, there is another way to gauge your hydration level. There are systems in your body that hold on to water if you are dehydrated and that means that urine volume goes down. However you still need to rid your body of all those waste products, which leaves urine looking darker so the colour of your urine is a very good indicator of your hydration status. It should be a pale straw colour, if it’s darker than that you need to top up!

Sources

Barker et al 2012, Hydration deficit after breakfast intake among British schoolchildren. Experimental Biology, San Diego, CA
EFSA: Scientific Opinion on theDietary Reference Values for Water –http://www.efsa.europa.eu/en/efsajournal/pub/1459.htm