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How Much Water Do You Need To Drink While Fasting? [Intermittent Fasting]

Updated: Jan 19, 2022

If you're using Intermittent Fasting to achieve a weight loss or wellness goal, how much water do you need to drink per day? Do you need to drink MORE water while using Intermittent Fasting? Today, we're diving into the details of water while Intermittent Fasting.

how much water should I drink a day

How Much Water Should You Drink Per Day?

A good rule of thumb when calculating your daily water needs is to aim for half your weight in ounces per day. For example, if you weigh 140 pounds, then you would aim for 70 oz. of water per day. However, if you are exercising or you live in a hot area where you're prone to sweat, you may want to add an additional 16 oz. or more per day to replace the water lost via sweat. One area that is rarely discussed when talking about water is salt replacement. This is especially important while fasting. We'll be discussing this in more detail later in this article.

Pssst - wondering what type of fasting is best for your goals? Click below for my free Intermittent Fasting Schedule quiz to find out!

Do You Need To Drink MORE Water While Fasting?

One of the main weight loss perks of Intermittent Fasting is that it naturally allows insulin (our storing hormone) to dip down, which then causes the fat burning process, called lipolysis, to turn on.(1) This is great for weight loss purposes! However, one thing to consider is that lower levels of insulin can signal the body to stop holding on as tightly to water and electrolytes (which is probably why you're peeing more often, too). This sudden decrease in water and electrolytes can cause dehydration. This is why it's particularly important to drink water during the fasted state so that you can replace what is lost while fasting.

A common mistake many people make is drinking coffee during the fasted state and not water. This can lead to further dehydration and make potential headaches or electrolyte imbalances even worse.

How Much Water Do You Need To Drink While Fasting?

This information will vary, depending on the type of fast discussed. However, for today's article, we're specifically discussing shorter fasts that range from 12-20 hours per day. I typically recommend to my clients to focus on around half of their daily water needs during their morning fast. So going back to that 70 oz. of water per day example, this would equate to a minimum of 35 oz. during the fasted state. If you're exercising during this time, remember to bump up that water intake by at least another 16 ounces.

But if you stop at this information, then you still will probably experience those pesky Intermittent Fasting headaches. And that's because you didn't address the vital electrolyte component.

How Much Salt Do You Need While Fasting?

Sodium is the main electrolyte lost when insulin levels start to dip down. Some experts estimate that individuals can lose anywhere between 2-5 GRAMS (2500-5000mg) of sodium per day while fasting. Another study found that around 1500 mg (1.5 grams) of sodium was lost per day while following a 7 day fast.(2) And this doesn't include if you're exercising and losing even more sodium via sweat. Sodium is needed to transmit signals from the brain to every part of your body. Because of this, common signs of electrolyte imbalance include fatigue and headache.

how much water should I drink a day

I typically prefer to use Celtic Sea Salt in my water during the fasted state to help balance electrolyte levels. I'll use around 1/4 tsp. in my first glass of water and another 1/4 tsp. after my workout. I also use Celtic Sea Salt in the ACV Sipper (from the Complete Intermittent Fasting Bundle) before breaking the fast. Simply drinking more water while fasting and not replacing the electrolytes can lead to an even further dilution of electrolytes. The amount needed per person will greatly vary. But one thing that is clearly evident -- sodium replacement is vital to maintain electrolyte balance.

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how much water should I drink a day

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Your Nutritionist,


how much water should I drink a day

Autumn Elle Nutrition

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