Intermittent Fasting 101

Intermittent fasting has become a popular trend over the past couple of years. Why? Well it has so many benefits, such as helping shed extra pounds, improving health, and helping you live longer! Contrary to popular belief, your body does not go into “starvation mode” or store fat when you go without eating for hours. A lot of studies show that intermittent fasting has many benefits for your body. So how do you go about starting and easing into intermittent fasting?

Types of Intermittent Fasting

different colored clocks of all sizes layered on top of each other
There are different kinds of intermittent fasting, and you can choose the time you want to start fasting and end it.

There are several ways of doing intermittent fasting. Some do it daily, while some people do it weekly. Here are the most popular forms of intermittent fasting:

  • 16/8– This is also called the Leangains protocol. For this kind of fast, you fast for 16 hours, and then consume all of your calories during the 8 hour window that you are not fasting. For example, you can begin fasting from 8pm until 12pm the next day (16 hours), and then can eat from 12pm-8pm. You can choose which hours work best for your schedule.
  • 20/4– The same concept applies as the 16/8 method, except you fast for 20 hours and eat during a 4 hour window.
  • East Stop Eat– This form of intermittent fasting requires more discipline. You fast for 24 hours for one or two non-consecutive days per week. The easiest way to do this kind of fasting is to fast from one day’s dinner to the next. You can do this from lunch to lunch, or breakfast to breakfast.
  • The 5:2 Diet– This diet focuses on the amount of calories you consume for the day. You limit caloric intake to 500-600 on two non-consecutive days of the week. Generally for this diet women should consume 500 calories, and men consume 600 calories. During the other 5 days you would eat normally.
  • Alternate Fasting– This is also called the ADF protocol. This is when you alternate between days of eating normally and days of fasting. You fast every other day, which may be harder for some to do. Studies have shown people are more likely to abandon their diet.

Can You Eat At All During Fasting?black coffee in a white mug on top of coffee beans

tea cup with tea in it and a daisy

Generally no. When you are fasting, all you can have is water, black coffee, tea, and other non-caloric beverages. The goal is not to consume any calories during the fast. When you fast, your body adjusts hormone levels to make stored body fat more accessible. 

Health Benefits

Reduced Insulin Resistance– During the fasting period, lower insulin levels improve fat burning in the body. Not only will it improve fat burning, but the lowered insulin levels will help encourage muscle growth. Studies show that fasting reduces insulin by 20-31%.

Detox The Body– When you fast, your body removes toxins. One way this occurs is from shedding weight. When you intermittently fast, your body will burn fat, using it for the energy it’s not getting from food. The fat cells are the usual culprits for toxin storage, keeping it from what we eat and breathe.

When you cleanse your body from toxins, you will find that you have more energy, stamina, clear skin, better brain function, and restful sleep patterns. 

Lose Weight– Because your body lowers it’s insulin levels, your body burns\ the fat for fuel, and it no longer receives the signal to store extra calories as fat. Intermittent fasting can increase norepinephrine, a hormone and neurotransmitter that can boost your metabolism! That way, your body will burn calories throughout the day.

caucasian belly with hands over the button in a heart shape, and a daisy over the belly button
Fasting boosts gut health and mood.


Improved Gut Health & Mood– Not only does your body burn more, but your gut health improves. Your mood and mental health go hand in hand with your gut microbiome. So, when your gut reboots due to intermittent fasting, your stomach and your mood are overall happier.

Heart Function– At least one study indicates that people who follow a fasting diet may have better heart health than people who don’t. When you fast, your levels of hemoglobin, red blood cell count are affected, in a good way. This improves heart health. 

Autophagy- The process of cells eating themselves to get rid of damaged cells, and recycle into better, more youthful ones is called autophagy. Viruses, bacteria, and other pathogens are destroyed in this process. The simple way to activate this is by fasting. Damaged cells are removed, and cellular and tissue rejuvenation occur.

Brain Function– Your body will burn glucose reserved in your blood and liver when you are fasting. The liver will turn the fat into ketones and use them for fuel. Your brain prefers ketones over glucose, and in turn, will work better and increase your ability to learn and think.

How It Affects Your Cells

Some of the changes your body will go through are:

  • Cellular Repair– Also known as autophagy, your cells break down and recycle old proteins that accumulate within cells, and make new healthy cells. Viruses, bacteria, and other pathogens are destroyed in this process. Damaged cells are removed, and cellular and tissue rejuvenation occur.
  • Growth Hormone– The levels of growth hormone increases by 5 times or more. This growth hormone aids in fat loss, and muscle gain.
  • Metabolic Rate– Your metabolic rate boosts as much as 3-14%when you are fasting for two days. However, other studies suggest that if you fast for longer than 48 hours, then you will slow down your metabolism.
  • Insulin– When fasting, your insulin levels stay low. Low insulin levels means that fat burning is increased. 

Easing Into Intermittent Fasting

It can be easy to begin fasting, but most people will give up within the first week, because they are not prepared. Some tips to make the transition easier:


  1. Start Slow– The easiest way to start fasting is by skipping a meal. Skip a meal, breakfast for example, and have water or coffee instead. You can eat lunch, which will break the fast.

    water bottle pouring water into a cup
    Drink a lot of water and electrolytes.
  2. Stay Hydrated– Drink a lot of water and electrolytes. This is very important for cognitive function. A plus is that water can help you feel full when you are hungry.
  3. Eat High-Quality Foods– When it comes time to break your fast, make sure to eat foods that are beneficial and essential to your health. Try to avoid junk food. Eat foods full of vitamins, minerals, and protein so you can fuel your body correctly. 
  4. Plan & Prepare– When you know when you are going to eat, it will make you obsess over the thought of food less. There are apps you can download that help you keep track of your fasting hours and send you notifications of when to start fasting, and when you have completed fasting and can eat. The app will have a timer to show how long you have been fasting, and how much longer you have 
  5. caucasian woman sleeping in a bed with white sheets and pillowcase
    Sleep is very important for cognitive productivity, fat loss, and metabolic reasons.

    to go.

  6. Sleep!– Get an adequate amount of sleep! Sleep is very important for cognitive productivity, fat loss, and metabolic reasons. When you do not sleep enough your hormones are affected as well as your insulin sensitivity. The less sleep you get, the hungrier you are. 

Consult With Your Doctor About Fasting If You:

  • Are underweight or have a history of eating disorders
  • Are pregnant or trying to conceive
  • Have a medical condition
  • Have diabetes
  • Have low blood pressure
  • Take medications

Fasting May Be The Key To Living Longer

Fasting is a practice that dates back through centuries in religion and cultures. Recently, fasting became quite popular in America due to the claims of health benefits, mainly weight loss. There are different kinds of fasting. There are fastings that take place over the course of 24-72 hours, and there is intermittent fasting. Intermittent fasting is when you cycle between periods of eating for a short window of a couple of hours and fasting anywhere from 16 hours to 20 hours a day. Research and studies have shown that fasting produces many health benefits, such as reducing diabetes, and better brain function. Healthy diet is also important and contributes to living longer, such as the mediterranean diet, and the chrono diet. Now there is a recent study that shows fasting is the new fountain of youth, helping you live longer.

sepia colored photo of an hour glass with sand spilling down.
Research conducted has shown that fasting can improve health, fight against diseases, and help a person live longer.

The Research That Backs It Up

There were multiple studies done on mice and people proving that intermittent fasting has many great health benefits. The studies conducted are:

  • In the 1980s, research revealed that lifespan of rats that fasted every other day increased substantially compared to rats who had food available at all times.
  • A study published last year in 2017 divided people into two groups. One group ate whatever they wanted, while the other group had to consume between 800 and 1,100 calories for only five days out of the month. The study was conducted over 3 months. The pattern of those that fasted is called a “fasting mimicking diet,” or “FMD.’ The people who did the FMD and were at risk for disease (whether diabetes, cardiovascular disease, etc) had their fasting glucose return to normal, lowering their risk for diabetes. Heart disease risks, cancer marks, and high levels of cholesterol all decreased. The participants also lost abdominal fat.
  • The 5:2 diet is a form of intermittent fasting where people eat what they want for 5 days and then for 2 consecutive days they limit their caloric intake to 500. The research was conducted on 100 overweight women. They were divided into 2 groups, one with the 5:2 diet and the other had 3 meals a day with reduced caloric intake by 20-25% of what they normally eat. The results were that both groups lost the same amount of body weight over 6 months, however, the group on the 5:2 diet had more health benefits. The participants’ glucose levels went down, lowering the risk for diabetes, and the belly fat loss lowered their risk factor for cardiovascular disease.
  • New research published in October 2018, randomly divided 292 male mice into two groups. One group was given low fat, and the other was given higher protein and fiber foods. Each group was then divided into 3 sub-groups. One group had access to food all day, the other ate 30% fewer calories a day than the 1st group, and the last one had access to food with the same amount of calories as the 1st group. The mice who fasted, whether because they were given all of their calories once per day, or because their calories were restricted, were healthier and lived longer compared to the mice who had constant food access.

    four mice poking their heads through a hole of a slice of bread.
    A study conducted on groups of mice revealed that the mice who fasted lived healthier and longer.

Stay Forever Young

Fasting helps you live longer because when you restrict food intake for a period of time, your body starts using ketones as fuel instead of glucose. When you repeat fasting, it can help optimize brain function and strengthen its resistance to stress and diseases. Not only will you live longer by fasting, but it is important to eat healthy when you do consume your calories for the day. The mediterranean diet has been proven to help improve one’s health and increase lifespan.

“We’ve published many papers, and the main thing we talk about is multisystem regeneration,” said Longo who runs the Longevity Institute at the University of Southern California’s Leonard Davis School of Gerontology. “For example, fasting seems to lower the level of damaged white blood cells — but when you re-feed, stem cells are turned on, and you rebuild and regenerate new, healthy cells,” explained Longo. “You get rid of the junk during starvation — and once you have food, you can rebuild. The damaged cells are replaced with new cells, working cells — and now the system starts working properly,” said Longo. This ultimately impacts disease risk, as risk factors for disease decrease when tissues are healthy and functional, explained Longo.

A Hopeful Future

As research suggests, fasting may just be the key to living longer. It enhances heart health, lowers the risk of diabetes, boosts brain function, aids in cancer prevention, and reduces weight! Trials are currently underway in order to determine if fasting can help slow down or even stop the progression of multiple sclerosis and cancer. Mark Mattson, chief of the Laboratory of Neurosciences at the National Institute on Aging explained that, “If you hit cancer cells with chemo or radiation, when the individual is in a fasting state, the cells may be more vulnerable to being killed because they use glucose and cannot use ketones [the source of fuel during fasting].”

One thing is for sure, fasting comes with many health benefits, but it is important to seek approval from your doctor before doing it! The goal is to stay as healthy as possible for as long as possible, and your doctor knows best. If you do decide to begin fasting, then start slow and progress over time how you (and your doctor) see fit.