We are currently experiencing hydration mania. On social media, water has swiftly become a health accessory. Influencers show off their latest Stanley cup collection worth hundreds of pounds whilst claiming that drinking water alone gave them glowing, clear skin.
While hydration is hugely important to various bodily functions, do we really need to drink several litres a day?
The i Paper asked dieticians to explain the common hydration myths we should ignore, and the rules to ditch.
You don’t need to drink three litres a day
It’s recommended by the NHS that adults aim to drink six to eight cups of fluid per day, averaging between 1.5 and two litres, under The Eatwell Guide. Drinking the recommended amount can support the immune system, maintain skin health, and help with energy and cognitive function. It’s also crucial for temperature regulation and joint lubrication.
But according to water treatment specialists Kinetico UK, only 53 per cent of people are getting the optimum amount of hydration.
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Luckily, for those who aren’t huge water fans, it can come from a variety of drinks, including low-fat milk and coffee. “Even drinks like cordial or sugar-free fizzy drinks count,” says Sue Baic, a registered dietitian and nutritionist. “Fruit juices and smoothies also count, and are one of your five a day. I always dilute juices to make them go further, and it makes them more hydrating.”
Priya Tew, specialist dietitian from Dietitian UK, says “there’s no one size fits all”. Our needs will change depending on body size, activity level and any medical factors.
If you’re 65+ , you need to drink more
The easiest way to spot dehydration is the colour of your urine – which should be a pale yellow. Not drinking enough water, or water-based fluidsm is usually the explanation for darker urine, but some medical conditions or medications can also alter this.
Thirst is also a good indicator, although Baic warns that children and older adults, typically over the age of 65, don not have strong thirst indicators and should “be encouraged to drink more”.
The thirst mechanism diminishes with age, and children struggle to communicate or realise they’re thirsty, leaving both age categories vulnerable to an increased risk of dehydration.
It’s possible to drink too much water
Hyponatremia is “water intoxication that occurs from people drinking very large volumes of water, which can then dilute the sodium levels in the blood,” says Baic. It is the most common type of electrolyte imbalance, and is often found in older adults (one study found it affects 15.9 per cent of elderly people), thanks to reduced kidney function.
It is rare for healthy adults to be affected by drinking too much water, but Baic says urine should be a “straw-coloured” and “pale”. If it’s clear and uncoloured, it could mean you are over-hydrated.
Excess water diluting the sodium in the body can take the sodium levels to below 135 mmol/L, which is considered “dangerously low”. Symptoms can include nausea, headaches, confusion and sometimes seizures. If left untreated, severe swelling can occur in tissue, including the brain.
Avoid flavoured water
Flavoured water, such as the typical strawberry or watermelon flavours on supermarket shelves, has no special health benefits, warns Baic. It’s best to choose water with no added sugar, as some contain high sugar content and artificial sweeteners.
Flavoured water can be made at home using fresh fruit and herbs, where it’s easy to control the ingredients, but it’s worth noting that this is for taste preference only.
Adding electrolytes to water is the latest social media craze. Typically found in powder form or tablets that can be added to water, they are a combination of salts and minerals that the body uses to regulate physiological functions. They leave experts divided.
Sam Impey, co-founder of the nutrition site Hexis, says that people who do big athletic events, such as marathons, should consider them for restoring their salt levels after exercise. But Chloe Thomas, a personal trainer, disagrees: “There’s a lot of unnecessary marketing around them and they’re not needed.”
Adding fruit to water is pointless
TikTok is ablaze with people adding citrus fruits and cucumbers to their water, claiming it can aid digestion. This, according to both Baic and Tew, is a myth.
“In terms of taste, it can be beneficial because a lot of people don’t like the taste of tap water, so adding a lemon, orange or even mint can make it taste better, which is good if you don’t drink a lot,” says Baic. “Nutritionally, it doesn’t make much difference. If you eat the fruit afterwards, you may get some vitamin C but you’ll only get the fibre and polyphenols if you actually eat it. It’s really just a taste thing.”
When it comes to digestion, it has no effect. “It’s a tasty way to make water more appealing but it’s no magic fix. Lemon water won’t detox your body, that’s what your livers and kidneys are for,” says Tew.
Water-based foods are hydrating
Baic says around 70 per cent of our fluid intake comes from liquids, but the remaining can come from water-based foods, including fruit, soup and vegetables.
Cucumbers, lettuce, strawberries, watermelon and celery are among the foods with the highest water content, and often contain other benefits. Watermelon contains antioxidants, strawberries are high in fibre and vitamin C. Celery can support heart health and suppress inflammation.
Don’t chug it
If you find yourself glugging a litre at a time, you may want to slow down. “It’s best to spread water out,” says Tew. “Drinking one litre in one go can leave you bloated, and your body can’t absorb it efficiently. Little and often is kinder to your body.”
Baic agrees. “It’s more efficient and easier to spread it out throughout the day as it’s more comfortable for our stomachs. It can sit in your stomach, making you feel bloated.”
She recommends having 250ml every few hours, and around mealtimes.
Filtered isn’t healthier or safer
As tap water is drinkable in the UK, and regularly checked for contaminants and chemicals, filtered water is neither safer nor healthier.
“It’s just a preference because it tends to taste slightly different, but in terms of health and safety, there’s no difference,” says Baic.
Bottled water can range from under £1 but brands like Fiji and Voss, up to £3, are on the rise. These bottles, Baic says, have no particular benefits, aside from being convenient on the go.
In the UK, around 60 per cent of people own a reusable bottle for water on the go, but it’s important to clean them, preferably daily, to avoid harmful bacteria growing.