Fasting, in its simplest terms, is to stop eating for a specific period of time.
For health reasons, most fasts last 12-24 hours and can go longer in some cases, like 3-7 days or more, but generally, shorter fasts are more common.
Fasting will not allow you to consume calories, but water, tea, and coffee are allowed to curb appetite and suppress hunger pangs.
Common in most religions like Christianity, Buddhism, Islam, Hinduism, and more, it’s believed by many religions and regions that fasting can help your body heal. The science proves this to be true. (1)
In the Muslim tradition of Ramadan, they fast for a full month from dawn to sunset.
Studying the cultures that do these kinds of fasts have allowed scientists to examine what happens within the human body for extended fasts.
Read on to understand its benefits.
Why Is Fasting Popular?
Aside from religious purposes, there’s several reasons to fast for your well-being.
The research shows that certain types of fasting protocols can help the body improve cholesterol, regulate blood pressure, maintain healthy glucose levels, regulate insulin, and a host of other benefits. (2)
Is It Safe?
Short-term fasts will be very beneficial to your body if you’re healthy. It can also aid in weight loss if that’s your goal. Check out fasting on keto to learn more.
Even though your body needs fuel for its survival, fasting can greatly impact getting your health back and making it better.
It’s always best to discuss first with your doctor before trying any kind of fasting protocol, especially if you’re taking any kind of medication, have eating disorders, or are pregnant.
Fasting has become a very popular way for people to lose weight even though its practice has been around for centuries.
There are a few different ways you can fast, and you’ll experience different benefits depending on the frequency of your fasts and how long you do them.
For most adults, anywhere from 16 hours to 72 hours are the most common length of fasts you’ll see.
Fasting has many benefits, including detoxifying the body, lowering cholesterol, reducing inflammation, and boosting the immune system.
One of the most important benefits of fasting is that it can help release toxins stored in fat cells.
Elimination of toxins can also help maintain a healthy weight.
Fasting Benefits By Hour
Do you know what your body does through each hour of fasting?
Below is a great breakdown of what takes place during specific fasting hours.
- 4-8 hour fasts
- Lowering of blood sugar
- Food has left the stomach
- No longer producing insulin
- 12-hour fasts
- The digestive system temporarily shuts down as new food hasn’t come in
- The body starts to heal itself
- Human Growth Hormone (HGH) increases in the body
- Blood sugar relaxes due to glucagon, which is a hormone in the pancreas which job is to promote breaking down glycogen to liver glucose
- 14-hour fasts
- The body can begin to start using fat storage as energy and fuel
- HGH increases more
- 16-hour fasts
- Fat burning in the body starts to pick up
- 18-hour fasts
- HGH increases even more
- 24-hour fasts
- Autophagy, which is your body beginning to clean out dead cells starts
- Glycogen stores are completely depleted
- You’re in ketosis, and ketone bodies are released in the bloodstream
- 36-hour fasts
- Autophagy increase by over 300%
- 48-hour fasts
- Autophagy continues to increase, but at a slower rate than before
- Your immune system regenerates and restores itself
- Inflammation in the body drastically reduces
- 72-hour fasts
- Autophagy continues cleaning out the damaged cells while regenerating new healthy cells to take their place.
24 vs. 36 hour fast
Aside from the difference in hours and not being able to fast every day for 24 hours, there are plenty of benefits to doing these longer fasts for the longevity of your body.
Yes, food is essential to survive, but if you’re thinking about experimenting with a 24-36 hour fast, you should think about when you can do them and plan accordingly.
Many doctors believe that a 24 hour fast done once a week throughout your life as an adult is an amazing way to prevent chronic disease from showing up as you age.
When heart disease, arterial disease, and diabetes develop for those later in life, your body would have had the chance to clean up what it needed to so that it can be healthier overall.
Patients who have type-2 diabetes have been shown to positively reverse insulin resistance and control blood sugar. (3)
48 vs. 72 hour fast
If you plan to do longer fasting protocols, like 48-72 hour fasts, know what you’re getting into before starting.
While both are great goals, both will give your body to burn through glycogen stores and shift into fat-burning mode known as ketosis.
When in ketosis, your body has completely depleted the glycogen levels derived from carbohydrates and is now using ketone bodies for energy.
During this time, your body will feel great after being able to rest from digestion, cleansing itself, and burning fat.
Sometimes, people want to push a little further and go for a full 72 hours and get even better benefits than fasts done for just 48 hours.
You’ll notice reduced inflammation in your body while having acute mental clarity. You’ll have a great amount of focus that will be very productive.
It’s advised to do a 72 hour fast at least once a year, but more like once a month to benefit from all it has to offer your body.
It can slow the aging process dramatically, and your brain, cells, and body will be thankful for it.
Types Of Fasting
There are many different kinds of fasting protocols you can do. Intermittent fasting, or the 16:8 method, is a popular one.
This fasting protocol allows for sixteen hours of normal eating and eight hours of fasting each day.
Some other methods include alternate-day fasting (ADF), the 5:2 diet, and the Warrior Diet.
Each of these kinds of fasting protocols is similar as you’ll be going without food but differ in their length of time for the fasting period.
Below are examples of popular fasting protocols and a little about each one.
Intermittent fasting, commonly known as IF, is a popular fasting protocol that the world is constantly buzzing about.
It’s a huge fitness trend because people have noticed weight loss, improved health, and a simpler lifestyle by practicing intermittent fasting.
Intermittent fasting is just a cycled eating pattern between periods of eating and not eating.
It’s not a diet since it doesn’t say what you can and can’t eat. It just gives you a period of when you can consume food.
The most common intermittent fasting protocol is 16-hour fasts, where you fast for 16 hours and eat within an 8-hour window.
The 16/8 fasting protocol is very simple to understand, safe to execute, and sustainable for the long term.
To begin, all you have to do is pick an 8 hour period of the day where you’ll consume your food and not eat the rest of those 16 hours.
Those 16 hours do need to be consecutive, though, to get the best benefit.
This fits in perfectly with most people’s busy lives because you can stop eating dinner at 6-8 pm and then just skip breakfast. You’ll eat lunch around 12, so that can be anywhere from 16 to 18 hours.
If you get hungry before lunch and your 16 hours are up, you can eat some fruit to hold you over until it’s time to eat lunch.
Just because that works for most people doesn’t mean that you can’t switch up the time you do it. Skipping breakfast seems to be the most convenient, but everyone’s lives and schedules will be different.
Stick to healthy and nutritious foods to really get the most from this protocol.
16 hour fast benefits
There’s a long list of health benefits associated with the 16/8 protocol of intermittent fasting.
People who do this are likely to see:
- Loss in weight
- Blood sugar improvement
- A longer, healthier life
The 20/4 fasting protocol is also called the “Warrior Diet.” It was created by Ori Hofmekler and made into a book where he details the experiences he had on this fasting regimen.
You would fast for 20 hours on this protocol and have a 4-hour window where you can eat food.
This diet mimics the way our ancestors used to eat. They would have to hunt and battle (hence warrior) and then come home after a full day and feast during the evening.
Other Popular Protocols
There are more fasting protocols you can try if you’d like to explore more of them.
These protocols include:
- 24-hour fasts. Also known as the Eat, Stop Eat diet, a 24 hour fast is when you don’t eat for 24 hours, usually 1-2 times per week. You’re allowed to have calorie-free drinks during your fasting periods, such as water, tea, or black coffee.
- Time-restricted feeding. When you follow a time-restricted feeding protocol, then you’re eating your meals during a specific window of time each day. Usually, the window of time people tend to eat in is around 6-12 hours. It’s up to the person to pick when that period is and when it fits their schedule the best.
- Alternate day fasting or “modified fasting.” Alternate-day fasting (ADF) or modified fasting is another way you can approach intermittent fasting. The idea is that you eat one day and fast the next, so you’re only eating half of the time. On the fasting days, it’s not a full fast. You’re allowed to consume 500 calories on those days.