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Water: How Much Water Should You Drink?

Summer is in full swing, whether you’re delving into a pot of strawberries and cream in a lush British park or relaxing with a mojito at a beach resort, it’s important to stay hydrated. There are lots of recommendations on how much water we should drink daily, from 8 glasses to 3 litres, or even more. So how much water should we really drink?

Before we get into quantities, let’s look at the qualities of water.

Why is water so important anyway?

Water is life’s most precious resource and around 60% of our weight is water. It is so essential that we would likely not live more than 3 days without it. It’s important for a whole host of bodily functions, including:

  • The regulation of body temperature
  • The removal of toxins and waste
  • The protection of our spinal cord
  • The cushioning of joints
  • The continuation of blood flow through the body
  • The transportation of nutrients to different parts of the body

Not drinking adequate amounts of water in the long term can impact any or all of these vital systems. In combination with a diet rich in fibre and low in saturated fats, drinking plenty of water also decreases the risk of developing certain cancers, such as colon and bladder cancers. Additionally, it is an important source of fluorine, which combines with the enamel in teeth and strengthens it, reducing risk of tooth decay and inhibits bacterial enzymes in the mouth.

In the short term, even mild levels of dehydration can trigger fatigue, disturb mood and limit concentration.

Ok, so water is important. But what happens when you become dehydrated?

The human body regulates bodily fluid balance by excretion, sweating and breathing. If fluid intake begins to drop, the body begins retaining water by less frequent urination or by higher absorption of water from food. At this point, feelings of thirst also occur. However, whilst the body’s thirst mechanisms are excellent, feelings of thirst only occur at a mild dehydration level of 1-2% of body weight, which can lead to:

  • Headache or dizziness
  • Central and muscle fatigue, irritability, exhaustion and muscle cramps
  • Nausea, gastro-intestinal distress and vomiting
  • Dark urine

Even mild levels of dehydration can have large impacts. For instance, for every 1% loss of body weight, heart rate rises by 5–8 beats per minute and 2% loss of body weight can reduce working capacity of muscle by up to 20%. Severe or persistent dehydration can lead to constipation, urinary and kidney failure, circulatory collapse (coma) and ultimately death.

Right, so dehydration is best avoided. How much should we drink to stay adequately hydrated?

Water requirement is individual to each person and depends on a number of factors, such as  your level

Water: How Much Water Should You Drink?of activity, age, health status and what you’re eating. The average person in Britain (which may differ to other countries as water loss also depends on the climate and altitude) loses around 2.8 litres per day, which is the amount that needs to be replaced.

However, this is just an average and varies from one person to the next. The good news is that there is an easy way to know how much you should be drinking, and that’s looking at your urine. It is by far the best indication of you hydration level. Ideally, your urine colour should fall between 1-3 on the scale on the right.

What can I consume to hydrate myself?

Not all lost fluids need to be replaced purely by drinking water. Water is the most efficient source, but any fluid counts toward that intake, including milk, coffee, tea and fruit juices—though these should not be drunk in excess due to their high sugar content. Most foods also contain some water, with fruits and vegetables being particularly high in water. Lettuce, for instance, consists of 90% water.

Alcohol and strong coffees act as diuretics (a beverage that encourages the production of urine). Since coffee is typically not binge-drunk, the consequences are not significant. In fact, a standard serving of tea or coffee may have very little diuretic effect. An Americano for instance, will still hydrate you adequately, as the water in the drink cancels out the diuretic effect from the caffeine.

I realise that drinking water is important, but I don’t particularly like water and/or often forget to drink it. Any recommendations?

A common reason for not drinking enough water is because we forget to do so. It is good practice to remind ourselves to fill up a large bottle and leave it somewhere in sight (for instance, at your desk) and make sure you to drink from it regularly. A helpful trick when wanting to drink more water is to have a trigger to remind you. For instance, this could be whenever you hear a certain word or sound.

Infusing your water is also a great way to make water more appealing (and also to pack it with more vitamins and minerals). You can try:

  • Slices of lemon, lime, orange or grapefruit
  • Grapes cut in half
  • Chopped up strawberries
  • Slices of cucumber
  • Herbs such as mint, rosemary, thyme and sage

Alternatively, take a handful of berries (frozen berries work even better in summer) and blend them with water. That’s a perfect way to stay cool!