How much water should we drink?

Written by William Fryer - MA Oxon

Without water, we die, quickly, much quicker from dehydration than from starvation. Water is probably the single most important substance in our bodies. Up with the air that we breathe it is what makes us work. We are around ¾ water, it is in our blood and most of our cells, it transmits nutrients round the body and helps flush the bad stuff away.

We lose water through sweat and through our urine and it is important that we replace it.

Thirst is, in fact, a lagging indicator. It is like an emergency signal to our body that only kicks in when we have lost around 1% of our body’s water. If you feel you are already drinking plenty of fluids and are still regularly getting thirsty it may be worth investigating this with your doctor.

None of us are the same and different conditions call for different measures. Our size, the amount of exercise we take and, as water is part of our cooling system, the weather will alter the amount of water we need to take on board.

The UK’s Department of Health has recommended – as a guide – a daily intake of 1.2-litres of fluid. They don’t prescribe water and pretty much everything we drink is based on water, but if you drink 1.2-litres of cola a day, you will be overdosing on sugar and caffeine.

This fluid is supplemented with water contained in the food we eat. Like us, plants and animals are mostly made up of water and we usually get around 1-litre of liquid from our foods.

Dehydration can make us unwell. Thirst is a danger sign, as are headaches, faintness, lethargy and dark urine (our urine should be a pale yellow). If you are feeling off colour, that age old prescription – have a glass of water – may well help you feel better.

The Department of Health guidelines come down unequivocally in favour of water as the best thirst quencher. Milk comes next, but can make us fat, and fruit juices are high in sugar and should be restricted to meal time drinking.

How much water should we drink?

Water has no calories, no sugar, no fat – in fact, if you use a water distiller it won’t add to your waistline, rot your teeth or make you feel jittery.

So, remember the Department of Health’s advice and take around six 200ml or eight 150ml glasses of water a day and you’ll soon be feeling on top of the world.