How much water do you really need to drink?

Water is vital for life.  But how much water do you really need to drink?  If there’s one thing I often hear clients say is that they feel they need to drink more water.  While some  clients I see could do with a higher water intake, others are quite adequately meeting their fluid requirements and are just causing themselves extra stress trying to drink down loads of fluids when they really don’t need to.

Ditching sugary beverages for some good old water is an excellent way to improve your health, after all sugary drinks are linked to excess weight gain, poor glycemic control and gout, and ensuring adequate fluid intake can help with constipation.  But do you really need to be drinking 3L plus of water a day?  Does drinking lots of water help “flush fat” from your body, as I’ve read on some Facebook pages?  Does more water help you detox?  Below I’ll share with you why water is so important and how much you really need to drink.

What do we use water for?

You probably already know that water is a big part of our bodies (around 60% for adults).  It’s a part of every single cell within our body.    Water is used in many processes within our bodies, including the breakdown of the macronutrients carbohydrate, protein and fat.

Water plays a role in regulation of temperature. What happens when you get hot?   You sweat! Sweat is made mainly of water, as well as some electrolytes.  Sweat helps cool the body when it evaporates from the skin.

Water also plays an vitally important role in transportation within the body. This includes getting nutrients into our cells as well as removing waste products from cells (1).

Our blood contains water and adequate water is necessary for optimal blood circulation.  When you’re dehydrated, there is less water in your blood, making it thicker.  Your heart has to pump harder to get the blood around your body to carry oxygen and nutrients to your cell. That’s why you can feel tired when you are dehydrated.

Hydration is essential for every single organ and system within the body, from the brain, to digestive system to the reproductive system.  That’s why severe dehydration leads to death. While that’s the serious end of the scale, mild dehydration does effect your wellbeing. Research shows that  mild dehydration can effect your concentration, alertness, short term memory and increase feelings of fatigue. It also effects sports performance. (2)

How much water do we really need to drink?

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Our fluid needs vary depending on a number of factors including the temperature and humidity and physical activity levels.  As a guideline, 8 glasses of water a day should be sufficient, however if you’re exercising you will need more.   Higher water intake doesn’t have any additional health benefits (3).  It won’t help you ‘flush fat’, it won’t help you detox (your body does a great job of that already), all it will do is give you more frequent trips to the toilet and increase your toilet paper bill 🙂

Thirst is only a roughly accurate indicator for hydration status.  When you feel thirsty, you are likely already slightly dehydrated.   A simple way to tell if you are hydrated is to look at your wee. It should be a pale yellow colour.  If it’s dark yellow, you could do with some more water.  Be aware that vitamin supplements can influence the colour of your urine – so if you are taking these, this chart will not be as useful.

For those who are doing lots of high intensity, or long distance exercise, and sweating a lot, you may need to pay more attention to your fluid needs for optimal sports performance and recovery.  This page gives some guidelines.

Do other fluids count?

Yes!  Tea, coffee, herbal teas do count towards your fluid intake.  While caffeine is a mild diuretic (meaning it makes you urinate), you don’t actually lose more water than you consume (4).  Overdoing the caffeine isn’t a good idea though as it can affect your sleep and leave you anxious and irritable.  Stick to a couple of cups of coffee a day.

So while water doesn’t help flush fat, or detox your body, it is a vital component of keeping our bodies functioning optimally.   In general, 8 glasses of water should be sufficient, but you’ll probably need more on hot days and when you are exercising.  Use the colour of your urine as a guide to keep yourself optimally hydrated.