Why and how much water should we drink during the day?
It is very common on the internet, on social media, or in everyday life to come across phrases like: “How much water did you drink today?”, “It is important to be hydrated!”, “You should drink a lot of water!”. But why is it so important? And how much water should we drink in a day? Water is, of course, very significant for our body. Every cell and tissue needs water for its functioning. Our body uses water in order to fuel our basic needs such as excretion of waste substances through urine or stool, maintaining body temperature, joint lubrication, and protection of tissues.[1]
We can’t function without water very long and dehydration leads to serious health issues. In this article we will not talk about the basic needs, we will focus more on the superficial benefits of drinking water in abundance. Because I do not suppose there is someone who doesn’t drink at least one glass of water a day so I don’t think it would benefit someone if I was highlighting the fact that without water you will probably die.
But what I suppose is the fact that there are few people who are not drinking enough – drinking two small glasses of water because they are not thirsty. And they can even feel the disadvantages of being dehydrated but they just don’t know it is because of it! So, here we go…
What benefits come with staying well hydrated?
First of the benefits, and one that was a great motivator for me to drink lots of water, was the prevention and treatment of headaches. Headaches are one of the first symptoms of dehydration. To me, it was a daily occurrence. But since I’ve been watching my daily intake of water, my head hurts only very rarely (and that is usually because of my period). A lot of people confirmed improvement in the frequency of daily headaches and also their intensity. So if you are experiencing something similar and drink one glass of water and maybe one cup of coffee, you should think about it.
Another point on this list is an improvement in digestion. The majority of studies that focused on the relation between water intake and constipation have proven a causal link. So if we drink more water, it is less probable that we will be constipated.[2] Water helps to dilute the stool and the whole passage of food in the intestines is smoother. But if you suffer from chronic constipation and you drink enough water and eat enough fiber, adding water won’t unfortunately help. In that case, the problem is somewhere else and you should seek professional help.
A huge benefit of drinking enough water has been shown during weight loss and feeling of satiety. In a study, where there were being examined two groups of women where one of them drank 500 ml of water before every meal (breakfast, lunch, and dinner) and the other didn’t have been proven that the group that drank the water was able to lose up to 44% more weight than the other one. And even the percentage of fat loss was higher.[3] Hunger is a thirst in disguise – such a cliché but a true one. If you drink enough water, you just won’t feel as hungry and therefore you will not eat like a big portion of food as you would if you didn’t drink any.
Water also helps us to better physical performance and overall energy. Our feeling of being energized is influenced by our brain function which relies intensely on our level of hydration. That is why drinking water influences our ability to concentrate and our overall mood. It has been proven that our feeling of thirst is not a reliable signifier of the need for water – if athletes drank more water even if they did not feel thirsty, their physical performance improved.[4]
The level of hydration is also important for our skin. It has been shown that with increasing water intake, the dryness of the skin improved as well. This benefit could be seen the best on elders or obese individuals as dry skin was a very common factor for those groups of people.[5]
Last but not least, drinking enough water can function as prevention of illnesses. Science inclines to a conclusion that with sufficient water intake we can prevent illnesses such as kidney stones and infections of the urinal tract.[6][7]
How much water is enough?
That is the ultimate question, isn’t it? But it is not as difficult to say. Into our water intake, we can calculate also the water in our food. Generally, it is advised to drink 2,7 litres of water for women and 3,7 litres for men, where 20% of that can be contained in food (and therefore the amount of water we should actually drink will be smaller). I’ve always heard to drink at least 1,5 – 2 litres of water for a small person such as me. Of course, it depends on how much you weigh and how tall you are. I, personally, drink somewhere between 2- 3,5 litres a day in which I don’t include coffee or water in my food. Everyone has different water needs and no calculation can determine that for you. It will also depend on factors such as:[8]
- Exercise and how much we sweat (some people sweat more than others)
- Environment and season – if we live in a hot and wet environment, it is advised to drink more water. That goes for different seasons as well. It is natural to drink more water in summer than in winter
- Overall physical condition – sometimes, during specific health conditions, it is better to drink more water than is usual, that is however important to discuss with a doctor
- Pregnancy and breast-feeding – during these life stages it is advised to drink more water for sufficient hydration
Water need can be therefore absolutely individual. But don’t consider that fact, that you are simply never thirsty as a signifier that you don’t need more water! If I drank only when I was thirsty, I would drink a litre of water at max in the past. Your body will ask for more water once it is getting it regularly. A good signifier for sufficient hydration is the colour of your urine. If it looks like someone just dropped a yellow highlighter into it, you definitely need more water. The Colour of your urine should be only very light yellow or translucent[9]:
The optimal colour can be seen on this picture in the blue square. I would only add that even if the colour of your urine resembles the yellow in the bottom of the blue square, it is quite on the edge and drinking more water won’t do any harm.
If you feel like you just can’t drink any more water…
It can be difficult to force oneself to drink more water. I understand, I had it the same. What helped me to drink more water was an establishment of a solid drinking routine. Today, I follow it unconsciously every day. I always drink 500ml during exercise, before I eat breakfast I drink another 500ml and before lunch another, so that is in total 1,5 litres of water and I haven’t even eaten my lunch yet! After lunch, I am not as strict anymore and I drink as much as I need which varies from 0,5 litres to another 1,5 litres, sometimes even more.
I don’t force myself to drink as much as possible, but my body started to be thirstier once I established this routine. I am not saying you have to follow the same routine like me, you can find one which will be optimal for you! If your body is never thirsty, it is good to help it mechanically at the start. It is quite normal that if you now drink half a liter every day, it would be almost impossible to jug three liters from now on. Start slowly with one glass of water, then maybe two and so on…your body will ask for it on its own eventually.
Drinking enough water can be sometimes very annoying, especially if you then need to visit the bathroom every half an hour. But it is really worth it to implement sufficient hydration every day. If you rarely drink water, try it and see for yourself that the difference in the long-term period will be significant.
[1] Mayo Clinic. “Water: How much should you drink every day?” Nutrition and Healthy Eating. mayoclinic.org. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256
[2]Boilesen SN, Tahan S, Dias FC, Melli LC, Morais MB. Water and fluid intake in the prevention and treatment of functional constipation in children and adolescents: is there evidence? J Pediatr (Rio J). 2017;93:320-327. https://pubmed.ncbi.nlm.nih.gov/28450053/
[3] Dennis EA, Dengo AL, Comber DL, Flack KD, Savla J, Davy KP, Davy BM. “Water consumption increases weight loss during a hypocaloric diet intervention in middle-aged and older adults.” Obesity (Silver Spring). 2010 Feb;18(2):300-307 https://pubmed.ncbi.nlm.nih.gov/19661958/
[4] Adams, J. D.; Sekiguchi, Yasuki; Suh, Hyun-Gyu; Seal, Adam D.; Sprong, Cameron A.; Kirkland, Tracie W.; Kavouras, Stravos A. “Dehydration Impairs Cycling Performance, Independently of Thirst: A Blinded Study”, Medicine & Science in Sports & Exercise: August 2018 – Volume 50 – Issue 8 – p 1697-1703 https://journals.lww.com/acsm-msse/Fulltext/2018/08000/Dehydration_Impairs_Cycling_Performance,.19.aspx
[5] Palma L, Marques LT, Bujan J, Rodrigues LM. “Dietary water affects human skin hydration and biomechanics.” Clin Cosmet Investig Dermatol. 2015 Aug 3;8:413-21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4529263/
[6] Hooton TM, Vecchio M, Iroz A, Tack I, Dornic Q, Seksek I, Lotan Y. “Effect of Increased Daily Water Intake in Premenopausal Women With Recurrent Urinary Tract Infections: A Randomized Clinical Trial.” JAMA Intern Med. 2018 Nov 1;178(11):1509-1515. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6584323/
[7] Fink HA, Akornor JW, Garimella PS, MacDonald R, Cutting A, Rutks IR, Monga M, Wilt TJ. “Diet, fluid, or supplements for secondary prevention of nephrolithiasis: a systematic review and meta-analysis of randomized trials.” Eur Urol. 2009 Jul;56(1):72-80. https://pubmed.ncbi.nlm.nih.gov/19321253/
[8] Mayo Clinic. “Water: How much should you drink every day?” Nutrition and Healthy Eating. mayoclinic.org. https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256
[9] Source: U.S. Army PublicHealth Command : https://gacc.nifc.gov/nwcc/content/pdfs/safety/DOD_Urine%20Color%20Test_Poster.pdf
