Nutritionist Sarah Di Lorenzo: Water and hydration, how important it is to brain and body

Water is essential to life. When I ask people how much water they drink a day most would say none at all but they do drink tea and coffee or two glasses.

But on the flipside there are others who walk around armed with water bottles, some very fancy to be sure they’re getting their adequate hydration.

Most of us would have heard at some point in our lives we need to drink eight glasses of water per day but it may surprise you that this advice is nutritional advice from 1945.

We have all accepted the eight glasses of water as fact and a theory as to why that was created is based on a fluid intake of 1ml per calorie of food consumed.

So for someone eating 2000 calories per day they need 2000ml of water but given we are all different shapes and sizes our water intake is individual.

So when it comes to how much water do we really need, I tell my patients it is 30ml per kg of your own body weight.

Not drinking enough water causes dehydration, defined as the loss of 2 per cent of body weight due to fluid loss and dehydration presents as fatigue as well hunger.

So many times when people feel they are hungry they are actually thirsty, which is why I always tell my patients when hungry outside of meals try a glass of water first.

Drinking water is so important for our brain and body and something we all need to be doing every day, and there are a few reasons why.

For physical performance and energy levels, dehydration impairs performance, increasing fatigue and motivation.

So before you train, have a big glass of water.

Water helps energise our muscles, muscle fatigue is when cells don’t maintain their balance of electrolytes and shrivel.

So don’t forget your water bottle when exercising.

When it comes to weight loss, drinking water may help you burn more calories, reduce appetite if consumed before a meal and can lower risk or weight regain.

When it comes to a migraine or headache, water can reduce the severity, duration and intensity.

Water is essential for healthy bowel function by relieving and preventing constipation.

Adequate hydration keeps things flowing along.

When you don’t have enough fluid the colon will pull water from the stool to maintain hydration and this is how you end up constipated.

When it comes to the health of our kidneys, drinking water can decrease the risk of kidney stones and there is some current research looking at the possibility of drinking water and lowering the risk of recurrent kidney stones in people that tend to have them.

Water helps maintain the balance of our body fluids, our body is made up of 60 per cent water.

The functions of body fluid and why this is so important are digestion, circulation, creating saliva, transportation of nutrients, maintaining body temperature and absorption.

Body fluid also transports waste products in and out of the cells.

The main toxin in the body is blood urea nitrogen, a water soluble waste that is able to pass through the kidneys and be removed in urine, so our kidneys can do an excellent job at cleaning and removing toxins as long as your fluid intake is there.

A way to know you are getting enough water is the colour and odour of your urine.

When the body is not getting enough the colour and odour is increased because the kidneys trap extra fluid for the body to function increasing risk of kidney stones.

Our brain communicates through the posterior pituitary gland with our kidney to tell it how much water to release as urine or what we need to hold on to.

When it comes to alcohol, it interferes with the brain and kidney communication causing excess in removal of fluids leading to dehydration.

Water gives our brain energy to function and this includes thought and memory processes plus water is needed for the production of hormones and neurotransmitters in the brain.

Water is so important for gorgeous glowing skin, our skin contains a lot of water and is a barrier to prevent excess fluid loss.

When dehydrated skin also appears more wrinkly there is some inspiration for you to go and grab a tall glass of water.

My tips to drink more water are to have a drink with every meal, add some fresh lemon or lime to your water if you need some flavour, set a timer in your phone to remind you to have a glass of water, grab a water bottle and consider drinking herbal teas count as a glass of water too.