Water. It covers most of the planet, makes up a lot of your body, and helps your organs function correctly. Most Americans don’t drink enough water. On average, adults in the US drank 44 fluid ounces a day during 2015-2018. But hydration is important to bodily function, can help your body maintain or lose weight, and aids digestion.

How Does Water Help Me Stay Healthy?

The adult human body is made up of up to 60% water. It is used by the brain to create hormones, by the digestion system to produce saliva, helps to maintain homeostasis (regulates body temperature), aids in cell function and reproduction, supports waste removal and detoxification, and many of your organs are primarily comprised of water.

Bodily Function

Your body requires water to function. But what happens when it is deprived of water?

  • Physical performance – when you exercise, your body excretes sweat, the muscles move, the lungs draw in breath, and the heart pumps blood to carry oxygen to your muscles. Everything speeds up to keep up with your movement. Dehydration can cause fatigue and can reduce your physical performance.
  • Cognitive decline – your brain is about 73% water. Water deprivation can decrease concentration, make it harder to stay alert, and affect your short-term memory.
  • Kidney function – kidneys aid in waste removal and regulate the fluid levels in the body. Inadequate water consumption can stress the kidneys, making it more difficult for your body to maintain fluid levels and remove toxins.
  • Skin – staying hydrated can improve the skin barrier function. It can also make dry skin look and feel better.

Biological Aging

In a study released by the National Institute of Health, researchers looked at serum sodium levels in study participants over a thirty-year period. Serum sodium goes up when water intake is decreased, so analyzing the serum sodium levels in a patient is a good indication of hydration.

In the study, they found that participants with higher serum sodium levels aged more quickly than participants with lower serum sodium levels. Those with higher serum sodium levels not only aged faster, but they were also at increased risk of premature death and certain diseases.

Weight Loss

It isn’t much of a surprise that drinking sugary drinks such as soda, sweet tea, or fruit juice can cause you to gain weight. But did you know that drinking water could help you lose weight?

In this study from the National Library of Medicine, researchers looked at the fluid intake of men and women between 40 and 64 over a four-year period. Study participants replaced sugar-sweetened beverages with water and gained less weight as a result.

In another remarkable study from the National Library of Medicine, 50 overweight women increased their water intake by 1.5 liters a day for 8 weeks. They didn’t make any other changes to their lifestyle but reported weight loss, lowered BMI, and decreased appetite.

Increased water consumption causes thermogenesis in the body – a process that burns energy to produce heat. Your body has a similar response when you eat protein. It helps you burn more energy (therefore, more fat as well) and satisfies your appetite for longer.

Disease Prevention

Lower body water content can increase your risk of heart failure, stroke, atrial fibrillation, peripheral artery disease, chronic lung disease, diabetes, and dementia. There is also strong evidence that proper hydration reduces the risk of certain diseases, such as urinary tract infection, hypertension, fatal coronary heart disease, venous thromboembolism, urolithiasis, bronchopulmonary disorders, and cerebral infarct.

How Much Water Should I Drink?

Have you ever heard of the ‘8×8’ rule? 8 glasses of water, 8 ounces each. Well, that used to be the recommendation for water consumption, and is still touted by many. However, every person is different. The amount of water your body needs may vary depending on your weight, activity level, medications, and environment.

A good rule of thumb is based on body weight. Aim to drink 1/3 to 1/2 of your body weight in ounces as a baseline, then add to it when you are active, if you take any medications that may dehydrate you, or if you live in a hot or humid climate. Keep in mind that not all your fluid intake has to be strictly water. Many foods and beverages contain water in some form, so give yourself grace if you don’t finish that last glass of water before bed.

What if I Don't Like Water?

I hear this all the time. “But I don’t like water.” I used to be that way, too, but now I love it. However, here are a few options to switch things up.

  1. Infuse your water with fruit. Many fruits not only taste good but have added nutrients or provide electrolytes. Try lemon, strawberries, watermelon, lime, or mint.
  2. Get a water filter. The tap water in our area tastes nasty to me. Our family uses a big 30 cup filter and I find myself refilling it over and over again.
  3. Add some flavor. I sometimes buy sugar-free water flavorings to change things up. But be careful with these and read the ingredient label before you buy them – sometimes they sneak ingredients in there I don’t want in my body.
  4. Try tea. I really enjoy herbal tea in the evenings, and it provides a welcome break from straight water. I usually sweeten with a little raw honey or stevia.

Once I started hydrating, I noticed it really was a little easier to lose weight. When I don’t drink enough water, I get a headache, my mouth gets dry, and I can’t focus.

Now, I always keep a water bottle with me. I find myself almost absent-mindedly sipping it sometimes (which isn’t necessarily a bad habit, but keep in mind that even good things can be bad in excess – it is possible to drink too much water). It is a little inconvenient because I find myself going to the bathroom more frequently, but the benefits certainly outweigh the drawbacks.

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Further Reading

Barry M Popkin, Kristen E D’Anci, Irwin H Rosenberg, Water, hydration, and health, Nutrition Reviews, Volume 68, Issue 8, 1 August 2010, Pages 439–458

Boschmann M, Steiniger J, Hille U, Tank J, Adams F, Sharma AM, Klaus S, Luft FC, Jordan J. Water-induced thermogenesis. J Clin Endocrinol Metab. 2003 Dec;88(12):6015-9. doi: 10.1210/jc.2003-030780. PMID: 14671205. > I found this study particularly interesting. Participants drank 500 ml of water and it increased their metabolic rate by 30% within 10 minutes. The increase lasted up to 40 minutes!

Vij VA, Joshi AS. Effect of ‘water induced thermogenesis’ on body weight, body mass index and body composition of overweight subjects. J Clin Diagn Res. 2013 Sep;7(9):1894-6. doi: 10.7860/JCDR/2013/5862.3344. Epub 2013 Sep 10. PMID: 24179891; PMCID: PMC3809630.

CDC Facts on Drinking Water and Intake

USGS Water and the Human Body

Comments (2)

  1. Reply

    Nice, thorough article, Emi. And according to your customized calculation, I’ve not been drinking nearly enough water. No wonder I keep getting those dehydration headaches!

    • Emily Flanders


      I always keep a water bottle with me. I have definitely noticed that I take more bathroom breaks since giving birth (especially when I drink enough water), but I definitely think staying hydrated is worth the inconvenience!

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