Gone are the days of thinking eight glasses of water a day are enough. Mpho Tshukudu, a nutrition dietician has thrown that theory on its head – your body weight and daily water intake go hand in hand. 

Water comprises 50 to 70% of an adult’s body weight, which must be regularly replenished through dietary intake, as the body has no provision for water storage. Tshukudu said a person’s daily water needs are determined by what is seen on the scale. 

“You need about 30 to 35ml per kg. So, if you weigh 100kg, you may need about 3 to 3.5 liters of water per day. If you weigh 65kg and you’re drinking 2L a day, that might be too much, it all depends,” she said. 

Fruit juices are not adequate 

A research report compiled by Friede Wenhold titled “Water in the nutritional health of individuals and households”, found that fruits and some vegetables have significant amounts of water.

 For example, strawberries, cucumbers, tomatoes, and watermelons contain up to 90% water. Apples, oranges, and pears contain between 80 and 90%, and eggs, peas, and some fish between 70 and 79%. Baked goods, pasta, nuts, and bread contain less than 70%.

The report showed that a healthy diet does not rely on fluids to provide energy or nutrient requirements. Water could be used to meet practically all the fluid needs of healthy individuals, and solid foods could provide energy and (non-water) nutrient needs.

Teaspoons of sugar

Although fruit has high volumes of water, Tshukudu said that drinking fruit juice is not enough to increase your water uptake and should not be seen as a substitute. This is because of the high percentages of sugar that are present in fruit. 

“The difference between a can of 100% fruit juice and water is about eight to nine teaspoons of sugar. People think fruit is healthy because it’s natural but it can still lead to weight gain, especially around the tummy. This could lead to heart disease and blood pressure, as well as all the other lifestyle diseases that we are struggling with. So, we shouldn’t look at fruits as our source of fluids,” she explained.

Sparkling water is water 

*Lusanda Dube, 29, is a Campaign Manager for a marketing company in Sandton. She rarely drinks still water and, has been drinking sparkling water for more than four years. 

“I started drinking sparkling water more regularly when I started my weight loss journey. I cut down on my sugar intake since alcohol and mixers are loaded with sugar. So, as a way to continue drinking but doing it ‘healthier’, I started mixing my whiskey or cognac with sparkling water,” said Dube. 

Dube said she prefers drinking sparkling water because “it has character.” She said she drinks between two and three litres on a good day. 

“Still water has no taste which makes it hard to stay motivated while drinking it for me. At least with sparkling water, there’s an itch to the throat and it sparkles, especially when served cold,” she said.

Tshukudu confirmed that if sparkling water is not sweetened or flavoured, it is the same as water. It just has bubbles.

“It doesn’t have much of an impact on people’s health. The people who usually struggle with sparkling water are those who can’t handle too much gas. If you are struggling with feeling bloated or experiencing heartburn, the gas will accelerate this. Otherwise, sparkling water is just fine.” 

Watch those kidneys 

Wenhold confirmed that chronic dehydration contributes to disease for many reasons. He wrote that the relationship between hydration and various diseases is mostly based on evidence from descriptive studies. Based on his review, one controlled trial supported the association between hydration and kidney stones, renal toxicity of certain drugs, and cystic fibrosis. 

Tshukudu agreed that dehydration can have a damaging effect on the kidneys. 

“One of the simple ways to check if you’re well-hydrated is by looking at your urine. If you’re well-hydrated, your urine should be a very faint yellow colour. If it starts looking dark yellow and has a strong odour, then it means you’re dehydrated. That can damage your kidneys.  Another warning sign is constipation,” she said.

Tshukudu added that a dry mouth and dizziness are warning signs to also look out for. 

Tips: Add some flavour 

Tshukudu said that an easy way to increase your daily water intake is to include water in your everyday routine.  

“For instance when you’ve been sleeping for over six hours and you haven’t had any water to drink, have some after brushing your teeth. I suggest that every time you come out of the bathroom, drink a cup of water,” she said.

She noted that some of the reasons why people don’t enjoy drinking water is because of the taste. Some municipalities have different coloured and tasting tap water which may put people off. 

Tshukudu advised flavouring your water with pieces of fruit to enhance the taste. 

“If you like the taste of lemon, you can add slices to your jug. Slices and pieces of fruit like grapes, watermelon, mint, strawberries, or cucumbers are good additions to add some flavour.  Another way to liven up your daily water intake every now and then is to make your own iced tea. Make some rooibos tea and let it cool before adding a few slices of oranges, grapes, or peaches. Drink it throughout the day. You can play around with different flavours for the teas,” she added.

Tshukudu emphasised that drinking water this way is a good source of hydration since it tastes nice but without sugar.

She has been practicing as an integrative and functional nutrition dietician for 18 years. Tshukudu also assists small companies with their menus and has a master’s degree in food culture, communication, and marketing. – Health-e News 

* Not her real name.