The most well-known guideline for daily water consumption comes from the United States, saying that everyone should drink 8 glasses of 8 ounces per day. If you ask your doctor, she will probably tell you that your daily coffees, teas, soups and other beverages can be included in your “8 glasses” since water is naturally found in all beverages and in most foods.
But why is it so important to be well hydrated at all times?
Water is an essential nutrient to life on Earth. Humans, in particular, cannot survive for more than a few days without drinking water or else major body functions will start to malfunction. Water itself is a universal solvent for fundamental nutrients and minerals in the body. Water also helps cushion internal organs, regulate body temperature, maintain optimal body acidity, and is a vital component for organs to function.
The old “8 of 8” phrase suggests that you need to drink about 1.9L per day to be well hydrated. That might sound like a lot to drink, but the National Institute of Health recommends even higher levels - 2.7L for adult females and 3.7L for adult males.
These are rough guidelines since each person’s required amount of water differs according to activity level, age and gender. For example, an active 28-year-old woman who does extreme fitness such as cross-fit will need more water to stay adequately hydrated than a 60-year-old man who does light jogging.
It’s been suggested that recommended water intake should be determined according to average caloric usage per day. In other words, more activity and more calories require more water for a person to stay hydrated, including water from food and other beverages like coffee, tea and juices.
The first part of the small intestine absorbs most of the fluids you drink and the amount absorbed is directly affected by quantity and how energy-rich the beverage is. When a beverage has more added ingredients, like fructose-glucose, corn syrup and modified milk ingredients, water is absorbed much more slowly than drinks with fewer ingredients.
This is especially important when you need to quickly replenish the fluid you’ve lost through sweat and to relieve the heat stress caused by an intense workout or a hot summer’s day. Sports drinks are often not the best way for athletes to recover and rehydrate since the drinks often contain high amounts of sugar and fructose, inhibiting effective rehydration.
Even if you’re not in a rush to rehydrate, drinking beverages full of sugar, high-fat milk and/or artificial ingredients greatly increases caloric intake without any additional positive health benefits. Additionally, many beverages with high sugar content and artificial ingredients, such as pop, many fruit juices and energy drinks populating supermarket shelves, have been shown to be directly linked to nutrition-related illnesses such as type II diabetes, high blood pressure, and obesity. It’s important to read the nutritional labels carefully when choosing such drinks. Make sure they are low in sugar or artificial sweeteners (e.g., less than 10g of carbohydrates per bottle).
Drinking water in regular intervals throughout the day is the best way to stay well hydrated in most situations. Make sure to drink plenty of water before beginning intense or prolonged exercise or going outside in hot weather. Be aware that thirst is often the first indicator of dehydration, especially during heat stress.
Remember to drink often, avoid soft drinks and limit caffeinated drinks to help reduce calorie intake and for better hydration!
Betty Lau holds a B.Sc in Biology from the University of Toronto. She is also an honours graduate of the Culinary Management Nutrition program from George Brown College, where she discovered a deep interest in food processing and product development. She has a passion for healthy foods and drinks that nourish the body and the mind.
Betty is the Food Process Manager at Zpirit Foods Inc., where she stays thoroughly hydrated with the flagship product Zpirit Infuzion.