Let’s start off by saying that fluid and hydration guidelines in general are pretty straight-forward in many ways. That being said, fluid balance and fluid-related complications can be very complex and challenging.
What do we mean by fluid?
When we think of hydration, we often think of water. Water is a fluid, but juice, milk, broth, coffee, even popsicles are also considered fluids. And while all of these fluids can contribute to our daily fluid intake and hydration, water is the important fluid to focus on, which we will discuss in more detail below.
So why are we even talking about fluid and hydration in the first place?
We often don’t think much about water and fail to recognize just how critical it is for our health and for sustaining many key metabolic functions and ultimately our survival. Water is the main component of our body making up around 50 to 70% of our body weight. Water helps to support our cells and organs and makes sure everything works like it’s supposed to!
Water plays many key roles including the following:
- Removes waste through urine, bowel movements, sweating and respiration
- Helps to support our joints keeping them lubricated and mobile
- Crucial for maintaining an appropriate temperature and reducing risk for dehydration and stroke
- Helps to maintain a normal blood pressure and blood sugars
- Helps to transport nutrients throughout the body
- And many other functions
So now we should have two very clear understandings
1. Water is not the only fluid. Juices, broths, coffee, etc. also count as fluids.
2. Water specifically plays many critical roles to support our daily functioning and is necessary for survival.
How do we know how much water or fluids we should be consuming?
As mentioned above, we lose fluids daily through breathing, perspiration, as well as excretion through urine and bowel movements. Therefore, we need to replenish these losses daily.
The amount of fluid we need depends on 3 key factors: gender, age, and physical activity level.
1. Gender
Males in general have a higher amount of water in their bodies. They also tend to have a higher amount of lean mass (muscle) compared to females who have a higher percentage of fat. Muscle holds more water than fat. Therefore, based on gender, males tend to require more water than females do.
2. Age
Age plays a more important role in children and adolescents due to growth and development. In general, children between the ages of 4 and 8 are recommended to drink around 40 ounces or 5 cups per day, while those ages 9 to 13 are advised to consume around 56 to 64 ounces or 7 to 8 cups per day. Those ages 14 to 18 are recommended to drink around 64 to 88 ounces or 8 to 11 cups. Once reaching the age of 19, the general recommendation for daily water and fluid for men 19 and older is 131 ounces or 13 cups while for women it is 95 ounces or 9 cups. However, there is a third factor that needs to be taken into consideration, which is physical activity level.
3. Physical Activity
Activity levels vary greatly from person to person. Children and adolescents tend to be quite active when young so this also needs to be factored in, but the same applies to adults. In general, the more activity a person engages in, the more water or fluids that needs to be replenished. For more information on physical activity and fluid requirements, visit the American Council on Exercise.
There are other factors too that need to be considered. For example, pregnant or breast feeding women also have higher fluid needs. Electrolytes should also be considered in instances where a lot of water is lost and replenished quickly.
For a starting point though, water and fluid needs can be estimated based on general guidelines for gender and age, as well as consideration of physical activity level. Water and fluid needs can also be calculated for each individual based on weight and fluid requirements per kilogram of weight for certain age ranges, which a Dietitian can help to determine.
If you are looking for more individualized nutrition support regarding hydration and nutritional requirements, schedule a virtual session with one of our Registered Dietitians!
Disclaimer: This information is for education purposes only and is not intended as medical or nutrition advice. See a Dietitian or Health Care Professional for any individualized medical or nutrition information.
Sources:
https://nap.nationalacademies.org/read/10925/chapter/6
https://www.unlockfood.ca/en/articles/water/facts-on-fluids-how-to-stay-hydrated.aspx
https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256#:~:text=The%20U.S.%20National%20Academies%20of,fluids%20a%20day%20for%20women
https://www.healthline.com/health/how-much-water-should-I-drink#recommendations
