We’ve all read varying pieces of advice about needing to drink 2-3 litres a day of water but have you stopped to think about why? And is this pure water, liquids in general, does water from food count? So many of us don’t drink enough water, which is more detrimental to the body than we realise. The body is like a car: if you don’t give it petrol or motor oil or wiper fluid or air in the tyres, the car will break down and stop working. The body, just like a car, needs to be provided with nutrients and water in order for it to be able to survive and work properly. It is able to live longer without food than it is without water, as hydration allows the body to be able to function properly.
Between 45% and 60% of the body is made up of water around (45% for children, 55% for women and 60% for men) and all of our tissues, organs and fluids have water as a main constituent. It allows the body’s organs (such as the lining of mucus membranes, the digestive tract and the bronchial tubes) to be kept moist and hydrated enough to the allow them to function without putting added pressure on other organs. If we take the kidneys as an example, their primary task is to remove waste and excess water from the body in the form of urine, as well as maintain a balance of salts and other substances in the blood. If the kidneys are not functioning properly because they are not hydrated enough, they will transfer most of their functions to the liver, which in turn will not be able to perform one of its mains tasks which is to metabolise stored fat. If there is no fat metabolisation then it means that the person in question will start to gain weight.
Water also helps to lubricate joints and membranes; it transport nutrients throughout the body; it dissolves minerals and other substances for the body to absorb; and it holds substances in colloidal suspension; it stays as a liquid over various temperatures. Water also acts as an appetite suppressant, therefore the feeling of satiety is reached quicker. If there is a higher intake of water, the person will eat less and the body will metabolise fat more efficiently.
There are 3 hormones that regulate fluid loss (antidiuretic hormone and aldosterone which help with slowing down fluid loss in the urine; and atrial natriuretic peptide which increases urine flow rate). Fluid intake is made up of fluids that are ingested, food that is ingested and metabolic water (resulting from metabolic reactions in the body). Water loss is made up of excretion/evaporation from the GI tract, the lungs, through the skin and the kidneys. This typically accounts for 2500 ml in water gain/loss. Exercise/illness will cause an excess of fluid excretion, therefore, replacing the water lost is important. It is also important to understand that the fluids in the body (digestive juices, mucus, saliva, blood, lymph, sweat, urine) also have an impact on regulating fluid loss as they account for varying amounts of fluid in the body.
It is important to ensure that there is not an overload of fluids at any one time, therefore allowing the body to process the fluids. This can be achieved by regular intakes of fluid throughout the day (regularly spacing out the normally recommended 2 litres a day throughout the day) to ensure the right balance in the body. Over-hydration can also impact the body by creating hyponatremia (a reduction in the salt level in the blood) resulting in an electrolyte disturbance.
When the body doesn’t receive any nutrition it goes into starvation mode and holds on to the fat that is currently in the body to allow it to feed off it to ensure its survival. The same happens with water – if the body doesn’t receive any fluids it will start to hold on to the fluids it currently has (in the extracellular spaces in the body), known as fluid retention. Fluid retention generally results in swollen feet, ankles, legs and hands. Once the body starts to receive liquids it then starts to release the water that it has been holding on to for survival. Fluid retention can also be caused by the person’s sodium intake being too high, which requires an excess of water to dilute it before it then goes to the kidneys to be processed.
Fluid retention also causes other organs to start to become dehydrated as the body tries to hold on to water. One very obvious sign of water retention (and therefore dehydration in that specific organ) is constipation – the colon becomes less moist (which has a direct impact on bowel movements) as the body retains the moisture in other organs. In the case of the kidneys, water retention can actually cause kidney failure as the kidneys are no longer able to remove excess water from the body in the form of urine.
The average person requires around 2 litres of water a day (and an additional 250ml for every 25lbs they are overweight by). In hot climates or during sport the requirement will be higher given the loss of fluid through sweating. Many of us can suffer mild symptoms of dehydration during the day (which include fatigue, loss of appetite, headaches, light-headedness, nausea or feeling excessively hot). You can also tell easily by the colour of your urine whether you are dehydrated – anything darker than pale yellow indicates that you need to drink more water.
There is the misconception that soft drinks or flavoured water can be counted towards the daily water intake requirement. While these will provide your body with the hydration needed, unfortunately, the amount of added sugar and chemicals that are in them will far outweigh any hydration benefits as you could be at risk of putting weight on, causing tooth decay or suffering an increase in blood sugar levels. Obesity in children is on the rise in Europe. In the UK the consumption of fizzy sugary drinks has doubled over the last 15 years and studies have shown that children and adults are missing out on essential nutrients in food because they are eating less at mealtimes following the constant consumption of fizzy drink.
It’s easy to drink water throughout the day. People who know me know that I never go anywhere without a bottle of water. If I am going to meetings at work (which is here I spend most of my day nowadays) I am usually clutching my 1L bottle of still water and I periodically sip it. I always carry a bottle of water in my handbag also. If you can make 1 important change to your lifestyle, decrease your consumption of sugary drinks and replace them with water. Sparkling water with a fresh berry or a slice of lemon in the glass will satisfy your craving for taste. Your body will love you for it!