What Counts as Your Daily Water Intake?

Water is so essential for survival that we can only last 2–3 days without it — and we all know what happens then... That is because people can become dehydrated quite quickly.

Why do we even need water

The human body consists mostly of water — it makes up around 60% of an adult's body weight.

Water is essential for many bodily functions, including:

• Metabolizing nutrients: Water is needed in the process of breaking down your food into smaller usable components. Blood, which is also partly made up of water, then transports these nutrients (and also oxygen) throughout your body for your cells to use them.

• Protecting mucosal membranes: You might not think about these in your everyday life, but they are actually very important for your health. These membranes, such as those in your airways, act as barriers against harmful pathogens. If dehydrated, they might dry out, making you more susceptible to infections.

• Regulating body temperature: When your body becomes too hot, it uses sweat to cool you down, keeping a stable body temperature.

• Eliminating waste: During metabolism, several waste products are formed that your body needs to get rid of. This is partly done by forming urine, which helps you remove them (no need for detox teas—water handles it just fine).

• Supporting brain function: Proper hydration keeps your brain functioning optimally.

• And much more.

Water balance: how much do we need to consume

We constantly lose water throughout the day — not just through urination but also through evaporation from the skin, sweat, and even breathing. The amount of water we lose depends on several factors, such as physical activity and climate. For instance, you are likely to lose more fluids in a hot climate compared to a cooler one.

To prevent dehydration and keep our bodies functioning properly, we must replenish lost fluids daily.

So, how much and what should we drink?

You may have heard of the 8x8 rule: it is often suggested to drink eight 8-ounce glasses of pure water. At least I remember being told this when I was younger, and that teas and coffees did not count as water. While the exact origin of this statement is unclear, it might trace back to Dr. Fredrick J. Stare, whose actual opinion was to drink around 6-8 glasses of fluids daily (including more than just water).[4]

What do health organizations suggest nowadays?

The European Food Safety Authority (EFSA) suggests that an adequate daily water intake is around 2 liters for women and 2.5 liters for men. These amounts are suggested for people who are moderately active and live in a climate with moderate temperature, as both these factors might affect your hydration needs.[2] The Nordic Nutrition Recommendations (NNR 2023) also align with the same amounts [1].

While it might sound similar to the 8x8 rule, these guidelines recognize that fluids don't come only from pure water. They include all beverages (tea, coffee, juice, water, etc.) and even food. Yes, even food contributes to your daily overall water intake. Typically, around 20%-30% of your daily water intake could come from food. [2]

“But isn’t coffee dehydrating?” you might ask. Well, I too have heard this claim almost all my life. Lucky for us coffee lovers, research indicates that moderate coffee consumption (up to 4 cups per day) doesn't significantly affect hydration levels.[3] However, that’s not to say that going above this limit might not exert some diuretic effects.

Now, before you think, “Great, I can just drink sodas instead of water,” it's important to remember: just because you can, doesn't mean you should. As we've emphasized before, nutritional guidelines still apply. Daily sugar limits exist for good reason.

How is Nutriely tracking water

Nutriely offers you to track your water intake based on these principles.

When you log our verified foods and drinks in your diary, their water content is automatically included in your daily water balance.

So, let me ask you: did you already drink water today? If not, this is your cue. Go, get a glass, and check whether you are adequately hydrating yourself on our app.

References:

1. Blomhoff, R., Andersen, R., Arnesen, E. K., Christensen, J. J., Eneroth, H., Erkkola, M., … Trolle, E. (2023). Nordic Nutrition Recommendations 2023: Integrating Environmental Aspects. https://doi.org/10.6027/nord2023-003

2. EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). (2010). Scientific Opinion on Dietary reference values for water. EFSA Journal, 8(3), 1459. https://doi.org/10.2903/j.efsa.2010.1459

3. Killer, S. C., Blannin, A. K., & Jeukendrup, A. E. (2014). No evidence of dehydration with moderate daily coffee intake: A counterbalanced cross-over study in a free-living population. PLoS One, 9(1), e84154. https://doi.org/10.1371/journal.pone.0084154

4. Valtin, H. (2002). “Drink at least eight glasses of water a day.” Really? Is there scientific evidence for “8 × 8”? American Journal of Physiology. Regulatory, Integrative and Comparative Physiology, 283(5), R993–R1004. https://doi.org/10.1152/ajpregu.00365.2002