72 Hour Fast: The Benefits of Water Fasting for Men Over 40

Written by: Erin Coleman,

B.S. - Nutritional Science, R.D., L.D.

Written by: Erin Coleman,

B.S. - Nutritional Science, R.D., L.D.

72 Hour Fast

Get ready to hit the reset button on your body with a 72-hour fast, also known as a three-day fast.

But before you jump in, it's crucial to approach it with caution and consult with a healthcare professional, especially if you have underlying medical conditions.

Surprisingly enough, a 72-hour fast offers numerous benefits for your well-being! It may seem counterintuitive to fast for several days without eating food, but longer fasts can actually do wonders for your health when completed properly.

Studies back the many benefits for healthy people of doing 24-hour, 48-hour, and even 72-hour fasts. Some people have successfully fasted even longer than three days!

One of the main perks of fasting is significant weight loss, thanks to the calorie deficit created during the fasting period. But that's not all! Studies suggest that fasting might improve insulin sensitivity and help regulate blood sugar levels, making it potentially beneficial for individuals with type 2 diabetes or insulin resistance.

But here's where things get really exciting. Extended fasting may stimulate autophagy — a cellular process that clears out damaged or malfunctioning cells and proteins. It's like hitting the refresh button on your cells, contributing to your overall cellular health.

And let's not forget about the mental benefits. Some people report improved mental clarity and focus during fasting periods, possibly because their blood sugar levels remain stable throughout the fast.

Experience the benefits of a 72-hour fast and see how it can supercharge your body and mind!

Find out what a 3-day water fast can do for your body and health!


Who Should (and Shouldn't) Do a 72 Hour Fast

A 72-hour (3-day) fast is a healthy fast in which you don't eat food and only drink water, coffee, or green tea for three days.

Though your body can survive fasting for longer than three days, completing a 72-hour fast is a task many adult men and women can safely do (with the right amount of willpower) without experiencing too many side effects.

Some people are better candidates for a 72-hour fast than others. A 3-day fast is a good option if you're generally in good health, want to improve your health, lose weight, or are interested in detoxifying your body. It's even appropriate for athletes!

As long as you don't have a medical condition, your body can safely handle fasting, even for 72 hours!

However, you should avoid a 72-hour fast if you:

  • Are pregnant, trying to become pregnant, or breastfeeding.
  • Have a history of an eating disorder.
  • Take medications to manage your blood sugar, or take medications with food.
  • Are underweight or have diabetes or another medical condition.

Talk with your doctor before a 72-hour fast to determine if it's a good match for you.

The Benefits of a 72 Hour Fast (Backed by Research)

A 3-day fast can offer numerous research-based benefits for your health and overall well-being. Examples include:

  • Healthier body weight
  • Improved mental willpower
  • Reduced cellular ‘garbage'
  • Less inflammation
  • Stronger immune system
  • Reduced body toxins
  • Activated cell pathways
  • Natural stem cell activation
  • Improved insulin sensitivity
  • Reduced risk of diabetes and other diseases
  • Improved focus
  • New neuron growth
  • Reduced risk of dementia
  • Improved quality of life
  • Enhanced health and well-being
  • Reduced risk of cancer
  • Less cell damage
  • Improved natural healing
  • Better mental clarity

Fasting helps the body find the balance between catabolic metabolism (breaking down tissues) and anabolic metabolism (building tissues).

While a 72-hour fast isn't necessarily easy, especially if it's your first time trying it, knowing more about the benefits of fasting helps you stay motivated to successfully complete a first 72-hour water fast!

In this episode of the Fit Father Project Podcast, Dr. A digs deep into his personal 3-day water fast protocol.


How to Complete an Effective 72 Hour Fast

Use the tips below to begin a safe, effective 3-day fast!

Properly Prepare for a Fast

You might want to try a 24-hour fast before attempting a 72-hour fast. Doing so makes a 3-day fast easier, as your body is more accustomed to transitioning from eating food to being in a fasted state.

Allow a significant amount of time to pass between fasts to help your body re-adjust to not eating versus eating a typical nutritious meal plan.

Set aside a 72-hour period of time to complete your fast. You may choose a weekend, a vacation, or simply a 3-day period in which you don't have a lot going on, so you can focus all your time and energy on the fast and staying relaxed.

Before you begin a 3-day fast, exercise for about an hour during the day and eat a nutritious meal (use the Perfect Plate method when planning the meal) in the evening. Avoid overeating during this last meal before your 72-hour fast.

Begin Your 72 Hour Fast

Consider beginning your 3-day fast the night of your last healthy meal. After finishing the meal, drink only water before you head to bed. The next day when you wake up, drink some more water. Aim to drink at least 3 liters of water daily, up to a gallon of water or more if needed to avoid dehydration during your 72-hour fast.

Drink mineral water, such as natural spring water, to maintain your body's electrolyte balance. You might also add 1/4 teaspoon of pink Himalayan salt to a gallon of water to boost the trace mineral content and optimize electrolyte balance.

You can drink herbal tea along with water but avoid caffeine if possible. If you need coffee or caffeinated tea to prevent caffeine withdrawal symptoms, add 1 cup of coffee or green tea to your fast meal plan in addition to water.

Continue to Fast

During the first day of fasting, your body taps into its carbohydrate stores. It uses these stores (glycogen stores) as fuel for your body and brain. After stored sugar gets depleted, your body then creates ketone bodies to burn stored body fat as energy.

When switching from stored carbohydrates and sugars for fuel to using ketone bodies for energy, you might experience fatigue, brain fog, mild flu-like symptoms, irritability, or mood swings. Fortunately, however, these side effects are temporary.

After an initial transition to using ketone bodies for fuel, at about day two to three, you can expect to have more energy and feel better overall.

Develop an Activity Routine

While you can exercise during a 72-hour fast if you'd like to, avoid long and strenuous workouts. Keep your body relaxed during most of the fast, or choose light cardiovascular workouts for 15-30 minutes. You may also opt for light strength training during a 3-day fast.

Spend time outdoors as often as you can and go for walks. Do a few full-body strength training exercises but steer clear of high-intensity interval training (HIIT) and other intense workouts during the fast.

Get Plenty of Rest

It's vital to get plenty of rest and sleep to ensure your body functions at its best while fasting. Listen to your body to know when to rest and get your body moving.

Try to sleep at least seven hours a night and take naps during the day if necessary. Read, relax, journal, meditate, or be spiritual during a 72-hour fast to optimize your well-being.

Obtain Support from Friends or Family

Completing a 3-day fast isn't necessarily an easy task, so it's important to have a strong social support network in place before you do so.

Recruit an adult friend or family member to fast with you. Keep each other accountable and motivated throughout the duration of your fast.

Encourage each other if a 3-day fast becomes difficult to avoid giving up, especially when you're around food.

Break the Fast Properly

It's crucial to properly ease out of a fast by gradually reintroducing foods. That's because while fasting, your stomach often shrinks and doesn't produce the digestive juices it does when you're following typical eating patterns.

Break a 3-day fast during dinner on day three by eating something easy to digest and light. Examples include eggs, avocados, fresh fruit, yogurt, broth, or soup.

About an hour later, eat a nutritious, well-balanced dinner using the Perfect Plate method.

Consume your meal slowly and listen to your body to avoid overindulging. Resume typical eating patterns the following day!

Additional Fasting Tips

The number of times you should attempt a 3-day fast depends on your lifestyle, schedule, health, and preferences.

An ideal frequency for completing a 72-hour fast is several times per year. But remember, if you have a history of eating disorders, diabetes, or another medical condition, or you take certain medications that require being taken with food, avoid a 72-hour fast.

If you're considering fasting for more than 72 hours, do so only under medical supervision. Case studies show people fasting for 7 days, 10 days, and even a year! However, completing long-term fasts (longer than 72 hours) without the help of a doctor can be dangerous.

If you can, try a 24-hour fast before you attempt longer fasts. If you struggle with a 24-hour fast, try first skipping certain meals or eating only during an eight-hour period. Less restrictive fasts are a good starting point if you're new to fasting.

Work your way up to a 24-hour and even a 48-hour fast before attempting a 72-hour fast. Doing so gets your body used to being without food and transitioning from burning carbohydrates for fuel to using ketone bodies for energy.

If you have successfully completed a 24-hour fast, had success, and are now ready to begin a 72-hour fast, follow the detailed instructions above to get started!

Learn about the benefits of fasting for one day and what it can do for your body.


Erin Coleman, B.S. - Nutritional Science, R.D., L.D.

Writer, The Fit Father Project

Erin Coleman is a registered and licensed dietitian with over 15 years of freelance writing experience.

She graduated with her Bachelor of Science degree in nutritional science from the University of Wisconsin-Madison, and completed her dietetic internship at Viterbo University in La Crosse, Wisconsin.

Prior to beginning her career in medical content writing, Erin worked as Health Educator for the University of Wisconsin-Madison Department of Internal Medicine.

Her published work appears on hundreds of health and fitness websites, and she’s currently working on publishing her first book! Erin is a wife, and a Mom to two beautiful children.

*Please know that weight loss results and health changes/improvements vary from individual to individual; you may not achieve similar results. Always consult with your doctor before making health decisions. This is not medical advice – simply very well-researched info on a 72-hour fast.

Written by: Erin Coleman,

B.S. - Nutritional Science, R.D., L.D.

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