How much water is enough? Hydration questions answered by Dr Finch

How much water should an adult drink per day? Does coffee cause dehydration? How come we don’t need to drink water at night? We posed these and other questions about hydration to Dr Will Finch, a Consultant Urological Surgeon at the Norfolk & Norwich University Hospital, NHS Trust.

Mild dehydration is said to have adverse effects on the body. What counts as mild dehydration, and how might a healthy person notice its effects?

“Mild dehydration is when your body doesn’t have as much water as it needs and begins to show signs relating to this. Mild dehydration can develop when you lose as little as 1.5% of your body’s water.
Some of the symptoms can be as simple as a dry or sticky mouth and, for some people, a slight headache or feeling thirsty.
The effects of not drinking enough in the work environment are being looked at more closely in the medical nutrition literature. It’s becoming clearer that remaining adequately hydrated has positive benefits on mental agility, motivation, concentration, and mood.”

How much water should an adult drink per day?

“How much water you really need to drink a day will depend on your activity, metabolism, climate you live in and size. Water needs also vary from day to day depending on what you are eating, your overall health, physical activity levels and the weather.
Men should aim for 3litres of fluid intake a day and women nearer 2litres” – around eight 8-ounce glasses.

Should a person drink water before they’re thirsty, or is thirst a pre-cursor to dehydration?

“It’s a really good idea to drink before you feel thirsty. Feeling thirsty is the body telling you that you are already mildly dehydrated. Water is also contained in our diet and the food we eat, but this should be in addition to drinking.”

Is it true that the colour of your urine is a good indicator of hydration?

“A really good way of telling how well hydrated you are is to look at the colour of your urine when you void. We are all really busy, especially in an office environment, so not drinking enough water and fluids during the day is a real risk.
Your urine should be colourless or like a light lemon squash. This is an easy way to tell if you are adequately hydrated. If your urine is darker than that, like orange squash or rusty coloured, you are dehydrated and not drinking enough. Keeping a close eye on the colour of your urine allows you to pick up mild hydration and act on it to remain optimally hydrated.
Making sure you are optimally hydrated with water throughout the day has a number of health benefits for common medical problems. Avoiding dehydration is the mainstay of preventing kidney stone formation, as it allows the body to dissolve and wash out the salts that can form kidney stones in some people.
Remaining hydrated with water can also have a calming effect on the bladder for men and women with irritable bladders, help prevent urinary infections, avoid constipation, keep your joints lubricated and your skin looking supple! Keeping your urine clear and dilute by adequately drinking has a number of global health benefits.”

Does coffee dehydrate you?

“Everything in moderation! Coffee has a variable amount of caffeine depending on whether it is brewed, instant or decaffeinated. It is well recognised that coffee is a mild diuretic, increasing urine production, but it’s unlikely to dehydrate you significantly.
Studies have shown that the body becomes accustomed to caffeine intake, and lower caffeine doses don’t cause a significant change in urine production. So, it appears that the fluid you gain as part of your coffee is probably more than the fluid you lose. Coffee in moderation shouldn’t dehydrate you.”

How come we don’t need to drink water at night?

“Overnight, the brain produces a chemical called anti diuretic hormone (ADH), which tells your kidneys to reduce urine output when you are asleep. When you are young, less than 20% of your total 24-hour urine production is at night.
This clever regulation of urine production overnight means the body can retain fluid overnight and not become dehydrated whilst you sleep.”

So, do we need to rehydrate when we wake up?

“It is best to spread your fluid intake out through the day so that the body remains hydrated for as long as possible during waking hours.
Just remember, checking the colour of your urine tells you how well hydrated you are. Lemon squash colour or lighter, you’re on track with your fluid intake, orange squash colour and darker, then you need a bit more fluid to avoid dehydration and its effects.”

Is it true that staying hydrated is said to boost the immune system?

“Lots of research is being undertaken in this area and we will learn more of the answers with time. One area of research is looking at marathon runners and understanding how dehydration affects their immune response.
Some studies have documented that prolonged or intensive exercise can dampen down the immune system. It has been suggested that maintaining hydration during exercise can protect the immune system by diluting some chemicals that dampen it down and maintaining adequate levels of other chemicals that help fight and prevent infections.
We still have a lot to learn, and we need further research looking at the role of hydration on the development, treatment, and prevention of illness in general.”

How we encourage good hydration habits in the workplace

So, adequate hydration is important for preventing some of the adverse effects of dehydration, such as brain fog, lethargy, and headaches. But we all need reminding sometimes.
We give all Borg & Overström employees reusable water bottles. Not only do they provide a larger supply of fluids, they’re also a visual reminder to drink plenty of water.
Of course, all our staff have access to fresh, filtered water via our multiple water dispensing points. We recommend positioning these next to your coffee and tea stations as another reminder to drink water.

For more information about reusable drinking bottles, or water dispensers, get in touch and we’ll connect you with a distributor.


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