How much water should we drink per day? What is the truth about the 3 liter recommendation?
Water is the source of all life on earth. Without it, we would not be here to start with, and without it, we can not survive. In fact, depending on the conditions, a human being can not go more than a few days without water. The human body is composed of 60% water – in terms of weight. Water is needed for pretty much every bodily function, from flushing toxins to carrying nutrients, to digesting, you name it. But exactly how much water should you drink a day?
What about drinking 3 liters of water per day?
Reality is that there is no scientific research behind this number. It’s probably a misconception based on research by the Food and Nutrition Board of the National Research Council in 1945 and the book Nutrition for Good Health from 1974. The latter states that we should consume the equivalent of 6-8 glasses per day incl fruit and veg, caffeinated and soft drinks, even beer. The BBC has a great article about the myth of 3 liters per day.
So how much water should I drink?
The generally accepted consensus is that a person should consume the equivalent of 6-8 glasses of 8-ounce a day. While this is a good guideline, some people might require more or less. This depends on how active you are, or where you live. For example, if you live in a hot region, you will sweat more, and need to rehydrate more often.
Water Consumption Guidelines by health institutions
The American IOM (Institute of Medicine) has set the following guidelines on fluid intake:
- For men: 13 cups (about 3 liters)
- For women: 9 cups (a little over 2 liters)
- For pregnant women: 10 cups (about 2.3 liters)
- For breastfeeding women: 12 cups (a little under 3 liters)
These guidelines can, of course, be adjusted, depending on your own needs. OM also estimates that about ⅕ of our intake comes from the food we eat. While coffee and tea have a bad reputation due to their diuretic properties, they do contribute to your fluid intake nonetheless.
Other guidelines by the National Acadademic of Sciences, Engineering and Medicine recommends slightly higher consumption with 3.7 liters for men and 2.7 liters for women.
Bottled or tap water?
In the U.S, tap water is regulated by the EPA (Environmental Protection Agency). EPA defines a list of contaminants which need to be regulated in drinking water, in order to protect public health. For each one of these contaminants, EPA sets a limit amount of acceptable concentration in public water systems. These contaminant standards are required by the Safe Drinking Water Act (SDWA).
On the other hand, bottled water which is a packaged good, is regulated by the FDA. Although both the EPA and FDA have similar quality standards, FDA standards are looser in terms of how often bottled water needs to be tested and they do not require companies to share their test results with consumers.
In most of Europe water is regulated by the safe drinking water directive by the EU. Local regulation by each country ensures that it's implemented. Bottled water regulation is generally less strict.
There is no evidence that bottled water is healthier. If anything, it is less regulated. In the U.S 45% of bottled water is just filtered tap water sold at a premium. For example, Dasani water is nothing more than glorified municipal tap water from Marietta, near Atlanta.
If you are worried about taste, lead, microplastics, or other contaminants – the cheapest and simplest solution is to get a high quality filter, such as EcoPro by TAPP Water. The EcoPro cartridges are recyclable, so you never have to use plastic related to water again.
Conclusion on 3 liters of water per day
- Drinking 8×8 or 3 liters of water per day is a myth but consuming water when you are thirsty is always good
- For most people it's recommended to consume between 2-4 liters of water per day through food and beverages
- There is no scientific evidence that bottled water is healthier than tap water or filtered tap water
- Avoid bottled water if you can as it’s expensive, inconvenient and bad for the environment
- If you don’t like the tap water taste or worry about contaminants then use an affordable faucet water filter such as EcoPro by TAPP Water