Did you know that about 60% of the human body is water? And according to the United States Geological Survey (USGS), it plays a vital role in a wide range of body processes :
- Saliva production
- Synthesis of hormones and neurotransmitters
- Regulating body temperature (through sweating and breathing)
- Acting as shock absorber in the brain and spine
- Supporting effective digestion
- Delivering oxygen to the body cells
- Joint lubrication
- Urine production
- Supporting body cells repair and growth
- Keeping mucous membranes intact
This way, water is an irreplaceable substance for our lives! And we have to supply ourselves with fresh, clean water daily in order to survive.
But how much water should we drink per day? What health benefits are associated with proper hydration? How to stay hydrated during the day? How much water is too much? This article will guide you through the answers of these frequently asked questions!
Let’s get started!
How much water to drink daily?
The general recommendations for water intake are 3 liters/day for adult men and 2.2 liters/day for adult women.  However, in practice, the exact daily amounts of water strongly depend on your sex, age, physical activity, geographical location, and other personal factors like health conditions and lifestyle habits.
So how many glasses of water do you need to drink to stay properly hydrated? According to Harvard Health Publishing, healthy adults (people who are not diagnosed with health conditions and don’t take any medications) could generally stick to 4-6 cups of water per day. 
That being said, there are still a lot of unknowns that may impact how many glasses of water to drink: the temperature outside, more physically active days, excess sodium consumption, etc. For that reason, consulting your healthcare provider on the amounts of water recommended specifically for you is the best way to go! 
According to the American Heart Association, feeling thirsty means that you are already partially dehydrated.  Instead, the source suggests that looking at the color of the urine might be a better indicator of hydration levels:
- Pale and clear urine likely means you are well hydrated
- Dark yellow/foggy urine might show you need to drink more fluids
Other symptoms of dehydration may include  :
- Dry mouth
- Extreme thirst
- No tears when crying
- Benefits of water
Drinking enough plain water (as well as consuming water from dietary sources like whole foods and tea) could be associated with various health benefits:
Reduced cravings for calorie-dense, low-nutrition foods
A 2016 study by the University of Illinois at Urbana-Champaign found that participants who increased their plain water consumption by one, two, or three cups reduced their calorie intake by 68 calories, sodium intake by 78 milligrams, and sugar consumption by 5-18 grams per day. Furthermore, the research suggests that increasing plain water consumption by just 1% may significantly decrease the cravings for calorie-dense low-nutritious foods. 
As the brain is composed of 73% water, it needs enough of the liquid to function properly.
According to a 2013 paper published in the ACSM’s Health & Fitness Journal, even mild dehydration may result in a decline in cognitive performance: reaction time, short-term memory, mood, vigilance, and related factors. 
Taking these findings into account, keeping yourself hydrated may play a key role in maintaining your brain sharp and well working.
Disease prevention and health promotion
Evidence suggests that sufficient fluid intake and hydration are important factors for the prevention of chronic and nutrition-related non-communicable diseases, as well as promoting overall health and wellbeing. 
In fact, sufficient hydration levels could be linked to prevention and symptom improvement of the following health conditions  :
- Kidney stones and kidney disease
- Dehydration associated with hypertension
- High blood sugar
- Heart disease, stroke, and blood clots formation
- Dental diseases
- Urinary tract infections
- Obesity-related diseases
- Digestion issues (including constipation)
Even though sweetened beverages, flavored soda, and soft drinks contain mostly water, they also have plenty of additives like sugar, aromas, flavors, colorants, etc. This way, the regular intake of such drinks is associated with high-calorie intake, increased risk of obesity, high blood sugar, and metabolic syndrome.  In that sense, the health benefits of plain water consumption are not applicable to the consumption of sweetened and flavored beverages.
When it comes to tea and caffeinated beverages, there are popular speculations that these drinks lead to dehydration and neutralize the benefits of sufficient plain water intake.
That being said, excess consumption of coffee and tea may cause other health issues unrelated to dehydration like upset stomach, increased heart rate, and insomnia, among others. 
How to stay hydrated?
The American Academy of Family Physicians shares various tips that can help you drink more water and stay hydrated during the day  :
- Take a (reusable) water bottle with you during the day and keep it near you
- If you don’t enjoy the taste of plain water, add a slice of lemon to it (or a piece of cucumber, or even a bunch of mint leaves)
- Drink water before, during, and after a workout
- Drink water if you feel hungry. Often thirst and hunger feel the same.
- Drink water on schedule and make it a habit if you tend to forget it. Setting an alarm or a timer for certain hours can help you drink water more consistently
- Drink water when you are dining at a restaurant
Besides, Harvard Health Publishing suggests that drinking fluids gradually and consistently throughout the day (and not lots of water at once) is an effective way to prevent dehydration. 
How much water is too much?
“Sufficient hydration” is a key term that aims to encourage drinking just the right amounts of water: no less, no more. In fact, drinking more fluids than your body can handle could be just as dangerous as severe dehydration! 
In fact, evidence suggests that the symptoms of dehydration and overhydration can mirror each other: both causing headaches, nausea, fatigue, and dizziness. 
Exceeding the daily water consumption recommendations (2.2 liters for adult women and 3 liters for men) may increase the risk of overhydration and health issues. For optimal hydration, consult your healthcare provider about how many glasses of water to drink daily!