Why water is so important

How H2O affects weight loss and overall health.
Published March 3, 2020

We all know it’s important to drink water – but how much are we really supposed to drink? And what are the actual, tangible benefits of drinking enough water? Here’s the scoop.


How much should you actually be drinking?


You’ve heard the old adage that you have to drink eight glasses of water a day – but that’s not scientifically proven. The truth is, each person’s hydration needs vary. And the other thing to keep in mind is that while water is the best fluid you can drink, all fluids you consume – milk, soup, juice, et cetera – count toward your hydration needs. And that includes coffee and tea, which despite acting as mild diuretics (they make you urinate) are not dehydrating.


The guidelines on what a recommended daily fluid intake vary.


According to the Dietitians of Canada, women 19 years and older need 9 cups (2 litres) of fluids a day, while women who are breastfeeding need 12.5. Men in the same age range need 12 cups (2.8 litres) a day.


The U.S. National Academies of Sciences, Engineering, and Medicine, on the other hand, has a slightly higher recommendation, suggesting about 15.5 cups of fluids for men and 11.5 cups for women each day.


Your lifestyle also helps determine what your daily fluid intake should be. If you live in a hot, humid environment where you sweat a lot, you may need more than the recommended average. The same goes for if you are exercising – you need to hydrate yourself to replenish the fluid lost when sweating.


How water affects overall health


Our bodies are mostly made up of water – about 60 per cent to be exact – so we need to be hydrated to function properly. Here are just some of the things our bodies need water for:

  • Creating saliva
  • Regulating body temperature
  • Lubricating joints
  • Excreting waste by sweating, urinating and through bowel movements
  • Digesting food and preventing constipation
  • Keeping circulation at optimal levels
  • Helping the brain function


How water affects weight loss


You may have heard that drinking more water can help you lose weight. There’s no hard and fast rule like “drinking X amount of water will make you lose X number of pounds”, but studies have shown that drinking more water can help with weight loss and weight maintenance.


There are two main reasons why: 1) drinking water can make you burn more calories; 2) drinking water can reduce your appetite.


Drinking water has been shown to increase adults’ calorie burn by between 24 per cent and 30 per cent within 10 minutes – an increase that lasts for about 60 minutes. And one study found that overweight women who increased their water intake to more than 1 litre a day lost an extra 4.4 pounds over a year – while making no other lifestyle changes.


As for the appetite factor, studies have shown that drinking water before a meal can reduce appetite, meaning you eat less, but this has mainly been proven among middle-aged and older adults. Studies of younger people haven’t revealed the same levels of reduced calorie consumption.


However, regardless of your age, the fact that water is a zero-calorie beverage means that you can reduce your overall calorie intake by choosing it over other higher-calorie drinks.


How do you know if you’re dehydrated?


There are three things you can monitor to see if you are drinking enough fluids, according to the Dietitians of Canada.

  • Thirst: Once you’re thirsty, you’re already a little dehydrated, so pay attention when you have a dry mouth and drink fluids throughout the day.
  • Urine: You’re aiming for clear or pale yellow urine – if you notice it’s darker in colour, has a strong smell or you’re simply not peeing much throughout the day, those are likely signs you need to hydrate more.
  • Mood: If you notice you’re tired, light-headed, having lots of headaches or trouble focusing, you might be dehydrated.