Like carbohydrates, fats, proteins, vitamins, and minerals, water is an essential nutrient for the human body. The main sources of water for the body obviously include water itself, but also other beverages such as tea and coffee, as well as foods, especially fruits and vegetables. Throughout the day, the body loses water through urine and stool, as well as through breathing, the skin, and sweat. This water loss can lead to dehydration and symptoms such as dry mouth, headaches, and difficulty concentrating. It is therefore important to regularly replace lost fluids throughout the day to reduce the risk of dehydration.
How much water should one drink daily?
The amount of water to drink each day varies depending on several factors such as physical activity level, age, and sex, as well as ambient temperature and humidity, and the presence or absence of certain symptoms like fever, vomiting, or diarrhea.
In Canada, recommendations are presented as Adequate Intakes (AI). These take into account total water intake, which includes drinking water and water provided by beverages and food. The recommended AI for total water intake for women aged 19 and over is 2.7 L/day and 3.7 L/day for men in the same age group. The recommended AI increases to 3 L/day for pregnant women and 3.8 L/day for those who are breastfeeding. However, water and beverages generally account for the majority of intake for most individuals. Excluding food, the recommended AI for women aged 19 and over is 2.2 L/day and 3 L/day for men in the same age group. The recommended AI increases to 2.3 L/day for pregnant women and 3.1 L/day for those who are breastfeeding.
Finally, as mentioned earlier, factors other than age and sex influence the amount of water needed. For example, daily requirements increase with physical activity, ambient temperature, and the presence of fever, vomiting, and diarrhea. Since water loss is increased in these situations, additional water intake is necessary to replace it and maintain an adequate level of hydration.
Which drinks contribute to total water intake?
Several drinks can contribute to total water intake. This is especially true for beverages such as tea, herbal teacoffee, milk, plant-based drinks, juices, etc. However, there are a few points to consider before choosing a beverage, including the content of free sugars, caffeine, and alcohol.
First, it is important to pay attention to the free sugar content of different beverages. Free sugars include monosaccharides (e.g., glucose, fructose) and disaccharides (e.g., sucrose or table sugar) added to foods and drinks, as well as sugars naturally present in honey, syrups, fruit juices, and fruit juice concentrates (WHO, 2015). For health reasons, the World Health Organization (WHO) recommends limiting free sugar intake to 50 grams (4 tablespoons) per day. According to the WHO, it would be even better for health to reduce free sugar intake to 25 grams (2 tablespoons) per day. Since drinks like iced teas, fruit juices, chocolate milk, soft drinks, and energy drinks can contain high amounts of free sugars, it is best to limit their consumption and replace them with water or unsweetened tea, herbal infusions, and coffee on a daily basis.
Secondly, attention should be paid to the caffeine content of caffeinated beverages. Drinks like tea and coffee are mainly composed of water and are good sources of hydration. In fact, research does not support the claim that caffeine has a diuretic effect that can lead to dehydration. Studies show that beyond 180 mg per day, caffeine may temporarily increase urination in some people, but this does not necessarily lead to dehydration. Therefore, caffeinated beverages such as tea and coffee contribute to total water intake. However, some drinks, like energy drinks, can contain a high amount of caffeine. As a reminder, Health Canada recommends limiting caffeine intake to 400 mg per day for adults, which is about eight cups of tea or two to three cups of coffee, and to 300 mg per day for pregnant or breastfeeding women, which is about six cups of tea or one to two cups of coffee.
Finally, the alcohol content of alcoholic beverages is another important aspect to consider. Indeed, alcohol promotes the elimination of water from the body by suppressing arginine vasopressin, an antidiuretic hormone that signals the kidneys to reduce urination and reabsorb water in the body. As a result, alcoholic drinks can increase the risk of dehydration and are not counted among beverages that contribute to total water intake. If you consume alcoholic beverages, it is recommended to do so in moderation, with food, and alternate with water to reduce the risk of dehydration.
Some tips for drinking more water
Water should be the drink of choice every day. However, some people may find it difficult to drink enough. Here are some tips to help you drink more:
- Drink a glass of water as soon as you wake up.
- Always have a reusable water bottle with you.
- Flavor your water with fruits, cucumber, lime, lemon, fresh herbs, and more.
- Drinking water during meals.
- Drink unsweetened herbal tea, tea, or coffee.
- Use an app to track your daily water intake.
- Be attentive to symptoms of dehydration: thirst, dry mouth, headaches, dark yellow urine, etc.
References
- https://www.canada.ca/content/dam/hc-sc/migration/hc-sc/fn-an/alt_formats/hpfb-dgpsa/pdf/nutrition/dri_tables-fra.pdf
- https://www.nchpad.org/1242/5916/Water~~The~Essential~Nutrient
- https://www.unlockfood.ca/en/Articles/Water/Facts-on-Fluids-How-to-stay-hydrated.aspx?aliaspath=%2fen%2fArticles%2fWater%2fFacts-on-Fluids-How-to-stay-hydrated
- https://www.hsph.harvard.edu/nutritionsource/water/
- https://www.nap.edu/read/10925/chapter/6#134
- https://www.hsph.harvard.edu/nutritionsource/healthy-drinks-full-story/
- https://www.hsph.harvard.edu/news/hsph-in-the-news/the-importance-of-hydration/
- https://www.cdc.gov/healthyweight/healthy_eating/water-and-healthier-drinks.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fhealthywater%2Fdrinking%2Fnutrition%2Findex.html
- https://www.unlockfood.ca/en/Articles/Caffeine/To-the-Last-Drop!.aspx