Recently I bought my grandpa a water bottle. You know, one of those ones with the volume markings so you can keep track of your progress through the day. I know it’s hardly a ‘stop press’ moment but you need to understand, he is 90 and likes to tell people that drinking water will “rust out your insides”, so him actually agreeing to use it and aim for two bottles a day was a big step.

This momentous occasion got me thinking – here is a man who just turned 90, always had an irregular heartbeat, boxed competitively through his 20s and worked a manual job all his working life. And here he is, kicking around in his 10^th decade despite his decision to blatantly ignore health advice about water intake (or eating that “rabbit food”). So, how important is water consumption, really, and how do I know how much I need every day?

Why do we need to drink water?

As John Mayer sang, “your body is a water-land” … or something along those lines. Anyway, our bodies are made up of 50-75% water, according to the Better Health Channel. Water forms the basis of our major body systems, from our blood and digestive juices through to our sweat, and is contained in our bones, muscle and fat. Dietitian Jenny Reimers said it is essential and our body needs it to function properly.

“Water is needed to help with our temperature regulation, our bowels and digestive system need it to ensure you are regular, our kidneys use water to flush waste – every cell in the body requires water,” Ms Reimers told Canstar.

How much water do the experts recommend I drink each day?

According to Ms Reimers, women should aim to consume eight glasses of water (about two litres) a day and men 10 (about 2.5 litres). However, this number varies for each individual for several reasons.

“While you can calculate the approximate recommended kilojoule intake for a person quite easily, water is very different because it can vary for each person depending on their body size as well as factors such as the temperature and amount of activity they are partaking in,” Ms Reimers said.

Women who are pregnant or lactating are recommended to consume more water, about 9-10 cups according to Ms Reimers.

But how do you know how much water you specifically need and whether you have had enough? Our bodies offer a useful gauge that does not require any dip stick. Just look at your urine.

“You want your urine to be a light lemonade colour,” Ms Reimers said.

The Better Health Channel provides the following breakdown of the approximate amount of liquids we may require. Keep in mind this is for all fluids, and as stated on its website, we absorb up to 30% of our water from food through the process of digestion.

* from breastmilk or formula
# from breastmilk, formula, food, plain water and other beverages
Source: Better Health Channel

Better Health Channel also states people may require more water than these guidelines if they:

• Eat a high-protein diet (to help the kidneys process the protein)
• Eat a high-fibre diet (to help prevent constipation)
• Have been vomiting or experiencing diarrhoea (to replace lost water)
• Are physically active (to replace water lost from sweating)
• Are exposed to hot temperatures (to replace water lost through sweat)

You may also want to increase your water intake if you have consumed alcohol.

Some people may require less water than others, such as those with kidney disease, heart failure or liver disease, according to healthdirect. If you have a pre-existing condition, it could be a good idea to speak to your GP about how much water you should be consuming.

What happens if I don’t drink enough water?

When the amount of water in your body is inadequate to meet its needs, dehydration occurs. Accredited sports dietitian at Resistance Sports Science, Renee Martin, said dehydration affects both mental and physical performance.

“Dehydration can lead to nausea, vomiting, diarrhoea and other gastro-intestinal issues,” Ms Martin told Canstar.

“It can impair physical skill level and cause mental fatigue, which can then impact concentration and decision making. If you’re being physically active while dehydrated, you could have an increased heart rate and body temperature and the exercise feels harder, especially in the heat.”

Ms Reimers added people in good health will generally know they are dehydrated if their mouth is dry, they are experiencing headaches, feel thirsty or have dark-coloured urine.

“Thirst is a fantastic indicator in a healthy individual and you should make sure you are drinking enough that you need to go to the toilet regularly through the day,” she said.

“But when checking the colour of your urine, keep in mind that supplements, such as a multivitamin, can impact this and make it darker, so in that instance it may not be a good indicator of your hydration.”

Excessive thirst and the need to urinate too regularly can be caused by other conditions such as diabetes, according to healthline.

To #SurviveTheHeat, remember to stay hydrated:

– Take small sips of water frequently
– Keep a full drink bottle with you
– If your doctor normally limits your fluids, check how much you should drink during hot weather

Learn more: https://t.co/fOgAd3iL51 pic.twitter.com/WLdnndRHwv

— Better Health (@BetterHealthGov) January 30, 2020

If I am exercising, or working in a manual job, how much more water do I need?

There are several factors that impact the amount of water you will need when you are being physically active, whether through exercising or working in a manual job. When we physically exert ourselves, our body forms sweat in a bid to cool our temperature, and the amount we sweat varies between individuals and can be impacted by temperature, wind and humidity.

According to Ms Martin, the amount you sweat will determine how much fluid you should be drinking.

“As your body continues to lose fluid through sweat and urine after you finish exercising, it is important to replace this fluid plus more over the next four to six hours (about 125%-150% of the fluid lost),” she said.

“Unfortunately, there is no one-size-fits-all approach to fluid intake – if you are unsure of how much sweat you produce and are concerned about how much fluid you should be drinking, it is recommended to see an accredited sports dietitian to assess your individual requirements.”

You can also monitor yourself for symptoms of dehydration and drink more water if needed.

But what about electrolytes – those essential minerals used in our bodies that can help keep you hydrated? When can they be handy?

“Whether or not someone requires water and sports drinks containing carbohydrates and electrolytes and when they should be consumed all depend on the age of the person, how much they are sweating and the intensity and duration of the activity or sport,” Ms Martin said.

Ms Reimers added that “you can use electrolytes to support hydration, but your body wants a quantity of fluid for its systems to work, so it shouldn’t replace drinking water”.

“Electrolytes like Hydralyte have a place, such as if someone has been sick, exposed to extreme heat or been participating in extreme physical activity.”

Can you drink too much water?

In summary, yes, but it is pretty hard to do. Ms Reimers said a healthy body usually does a good job of maintaining a balance (reading between the lines, that means we generally urinate more if we drink more, helping us maintain an equilibrium). But if someone does consume too much water, it can decrease the sodium (which is an electrolyte) concentration relative to water in the body and this is called hyponatremia.

“People at risk include those who do extreme physical activity, like iron man or ultra-marathons, where their electrolytes are depleted through sweat and then consuming lots of water further throws out their balance,” she said.

“This can impact a range of the body’s systems but, in general, you would feel confused and nauseous and could vomit.”

According to NPS MedicineWise, hyponatraemia can also be caused by certain drugs or conditions sch as heart failure and in its severe form can be very serious. If you think you may be at risk of hyponatraemia, speak to your GP.

Everyday you should be aiming to drink between 6-8 glasses of water, but did you know you can also eat some? 🚰 pic.twitter.com/tuEr4nD499

— Queensland Health (@qldhealthnews) January 19, 2020

Does drinking water help you to lose weight?

There are plenty of articles out there that tell you that drinking more water will help you lose weight – whether it fills you up and prevents hunger or helps flush out waste from the body (mostly by preventing constipation). But can I really drink my way to a slimmer body?

“Drinking enough water may assist in some weight loss, however it is only a small piece of the puzzle,” Ms Martin said.

“Ensuring you are well hydrated means that you may prevent yourself from unnecessary extra eating, as often when we think we are hungry we are actually thirsty.

“Before you grab something to munch on ask yourself ‘have I drunk enough water today?’ and practice drinking a glass of water and waiting 20 minutes to see if it is true hunger or if you were indeed only thirsty.

“Also, if you swap soft drink or other sugary or energy-dense drinks for water, you will remove additional and unnecessary kilojoules (calories) from your diet.”

5 tips to increase water intake

Many of us know we should probably drink more water but have several reasons why we may find it challenging to do so, whether we simply forget to drink through the day, prefer the flavour of other drinks or just aren’t in the habit of carrying a water bottle with us.

There are a few things we can do to boost our water consumption. Here are five tips from Ms Reimers and Ms Martin for simple ways you can increase your water intake:

1. Jazz up your water by adding fruit (such as lemon or berries), cucumber or mint to cold water or sipping caffeine-free herbal teas (note that teas with caffeine can have a diuretic effect so are not as effective), which may help you to drink more through the day
2. Aim for your ‘two and five’ servings of fruit and vegetables, because all fruit and veg contain water that you absorb when you eat them – the juicier they are, the more water they likely contain (think tomatoes, cucumbers, lettuce and watermelon)
3. Incorporate more water-rich foods in your diet, including soups, casseroles, broths, milk, yoghurt and even rice and pasta
4. Switch out soft drink or sugary beverages ideally for plain water, but if you’re after something a bit different, try having soda water with fruits or herbs; just be aware some studies indicate the acidity of sparkling drinks, including soda water, can be detrimental to your tooth enamel, but natural soda water is considered less damaging that other soft drinks
5. Carry a water bottle with you and be like my grandpa, as it acts as a prompt to remind you to drink regularly

In summary, water is a vital component of our bodies and is needed for pretty much everything. So basically, keep sipping, Pop, and maybe try munching on some of those “rabbit food” greens to help get your count up – your insides with thank you for it.

Feature image source: Nick Fox (Shutterstock)