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How Much Water Should You Drink a Day to Lose Weight

various water bottlesI’ve seen water recommendations all over the map for weight loss. Some bodybuilders drink in excess of 2 gallons of water a day, while others think anything more than a half gallon is overkill. So who’s right?

The Argument is Wrong From the Start

First of all, trying to give a blanket water recommendation is impossible. People are eating different foods that have different impacts on liquid intake (many whole foods are very water dense), and they have a wide range of differences in physical activity. Yes, water is extremely important for weight loss and good health.

However, it is not the end-all-be-all. Adding more water up and beyond what you need is not going to give you any added benefits. In fact, it can cause you more harm than good, as it can affect electrolyte balance.

Focus on the Quality of Your Liquid Intake

Just as how the quality of your food choices is what’s most important for health, performance, and body composition, the quality of your liquid intake is also what’s most important. You should be working towards eliminating the majority of your non-water liquid intake from your diet and replacing it with water.

If 90% of your liquid intake isn’t water, that should be your primary goal. It’s time to get rid of the sodas and other sugary drinks, and start replacing them with water. Getting your liquid intake to 90% water is one of the single best things you can do for your health and for losing weight.

Here are 26 shocking reasons to give up soda for your health.

How Much Should You Drink?

The Institute of Medicine’s Food and Nutrition Board recommends a fluid intake of 91 ounces for women, and 125 ounces for men [1]. For men, this is about 1 gallon per day. Keep in mind that fluid intakes can be influenced by:

  • Physical activity – the more active you are, the more fluids you will need.
  • Temperature – when it’s hot outside your body will sweat and release fluids to cool itself. The hotter it is, the more fluids you will need.
  • Carbohydrate – carbohydrates need water to form glycogen. If you eat a diet that is high in carbohydrates, your water requirements will increase.
  • Food quality – the more whole foods you eat, the less water you will need. Most whole foods have a high water density, and up to 20% or more of your water intake can be fulfilled from simply eating whole foods. On the other hand, processed foods increase the requirement for liquids.

Drink When You Are Thirsty

Your body is pretty good at telling you what you need. If you already have 90% of your liquid intake as water, then listening to your body is going to be your best bet. For the majority of healthy adults, thirst is a good indicator for telling you when to drink.

Keep in mind that our bodies are never at a perfect hydration level. We are either slightly dehydrated, or we are over-hydrated, and as a result, our bodies signal us to either drink (thirst) or stop drinking. So long as you don’t ignore your thirst cues, being 1-2% dehydrated isn’t going to negatively impact you any more than being 1-2% over-hydrated will.

It’s excessive dehydration that you have to worry about. Studies show that being more than 2% dehydrated can affect performance [2]. But if you’re mindful of your thirst cues, and you’re a healthy adult, you should never get to that point.

Water makes everything in your body work more efficiently. From fat loss to lubricating your nose, it is involved in every human function. Make sure you are staying hydrated, but don’t take a good thing and make it bad. Stay in touch with your body and don’t force it.

  • Me

    Does adding “crystal light” to the water affect it’s role in weight loss? Does it have to be plain water?

  • Lynda

    Hi Tony, thank you for another good article. Actually here you are talking to the converted. I drink 2 plus liters per day, have done so for about 2 years, and my body now tells me when I have not had enough.

  • Coach Calorie

    Great to hear Lynda :)

  • Coach Calorie

    I would not mess with that stuff, as it has artificial sweeteners. If you need some flavoring, add lemon, lime, orange, or cucumber slices to your water.

  • Jesus De Leon

    Yeah I have a question
    Isn’t it bad to wait until you’re thirsty to drink water? Doesn’t it mean you’re dehydrated by the time you’re thirsty?
    Hopefully you can answer my question :)

  • Coach Calorie

    I have heard that before, but I’ve never seen any scientific literature showing it. They might say dehydrated, and that might be true in a technical sense, but to what degree? I don’t think 5% dehydration is anything to worry about, and it’s better than being overhydrated in my opinion.

    • Jesus De Leon

      Interesting, why do you say dehydrated is better than being over hydrated?

  • Coach Calorie

    Overhydration can flush out important electrolytes, and can even result in complications in some instances. Slight dehydration (waiting until you’re thirsty is much less harmful IMO).

  • Nikkodawg

    I enjoyed the article in the email sent to me today “Why the opposite of fit is NOT fat”. As a life long fitness and health enthusiast, I’ve learned most of my knowledge from mistakes. One underlying truth of this article, really, is that it really is a lifestyle and that losing weight is just part of it. People get stuck on not being fat and many times miss the fit side of it. Many great inspirations, truths, reminders and supporting declarations in this article. Great job!

  • Deanna Schober

    Thank you!!

  • sallyw

    My urologist just said to have a glass of water every time you pee.

  • Sheila

    Odd question: I hear drinking room temperature water might be better for your system than cold water? Old wives tale?

    • Coach Calorie

      Haven’t heard that myself.

    • Mark Pryke

      its one of those debatable sayings, some say cold water is better, some say room temperature, in truth there is nothing to say one is better than the other as your body will take it to its core temperature no matter if its cold or room temp.

  • housedoll36

    Do herbal teas count as water? I find peppermint, fennel or similar much easier to drink as plain water. I don’t add sugar of course. Thanks

    • Coach Calorie

      Caffeine has a dehydrating effect, so it’s not quite the same. Try adding a slice of lemon, lime, or orange to your water.

  • Jackie

    I am finding that the more water i drink and even if when at fitness classes in the am, that i bloat as if the water is the cause for it as i would have eaten something healthy and have a clean diet?