Benefits of Fasting


Below is a letter sent to me from one of my client and friend of mine Dr. David DeAtkin he is a super smart forward thinking Endocrinologist . 
Check out our 360PT 21 Day Challenge if you would like to see how you can work Intermittent fasting very easily into your daily routine.
I don't only want people to follow the blue print we lay out I also want to educate you along the way . By understanding how some of the mechanisms of action work I think it makes it more interesting and motivating when you realize why you are doing it.

So please take a quick look at the article below it was written as a memo to a group of Doctors but I think its pretty easy for anyone to understand the principles and benefits.

Michael Brooks
Head Coach -


The subject of this MDVIP Academy may generate some discussion.  The topic is fasting, and what follows is essentially a review of a new book titled The Complete Guide to Fastingby Jason Fung.

Both short and long periods of fasting can be an incredible tool for prevention and reversal of certain diseases.  Before considering the concept of fasting, we need to remind ourselves that the “eat less, move more” approach almost never produces sustained success for those struggling with obesity.  Why do you think there has never been a reunion show for The Biggest Loser?  Obesity is a hormonal process.  Decrease insulin, and typically weight will drop.  Give insulin to a type 2 diabetic, and it is like pouring gasoline on a fire.  Weight never drops because insulin doesn’t allow access to fat as a source of energy.


Many of us eat more energy than we can use and the remainder gets stored.  Everything we eat leads to insulin release, except fat, which is why so many of us advocate for high-fat, low-carb diets.  When fasting, insulin drops.  When eating, insulin increases.  What about eating small, frequent meals?  For some, this means constantly elevated insulin levels and no fat burning.


We experience several physiologic phases during a fast:

1.    Postabsorptive – 6 to 24 hours after last meal.  Glucose and insulin start dropping, and we begin to break down stored glycogen in the liver and turn it into glucose for energy (since there isn’t any food intake).

2.    Gluconeogenesis - 24 to 36 hours after last meal.  Glycogen is gone (there are about 2,000 calories of glycogen in the liver).  The liver begins to make glucose out of amino acids.

3.    Ketosis - two to three days into the fast.  The decreased insulin stimulates lipolysis (the breakdown of fat).  Stored triglycerides are broken down into glycerol and free fatty acids.  Glycerol takes the place of amino acids and is used for gluconeogenesis (thus preventing muscle breakdown).  The fatty acids are used by most body tissues for energy and the liver converts them into ketones, a far more efficient and energizing fuel source.  After four days, 75 percent of the energy used in the body comes from ketones, which increase 70-fold during fasting.

4.    Protein Conservation - five days into the fast.  Growth hormone levels increase and maintain muscle mass.  Blood glucose is being maintained by glycerol.  Norepinephrine levels increase, which prevents a decrease in metabolic rate and is responsible for a sense of increased energy.  Most people expect to feel drained and tired during a fast.  In fact, the opposite happens!  Most people describe a euphoric feeling as early as day three.


Periods of low food availability are a normal part of history.  Many expect that not eating will cause metabolism to drop.  Actually, resting energy expenditure (basal metabolic rate) increases 12 percent during fasting.  Fasting happens to be the most natural stimulus for growth hormone production, which was shown to double during a five-day fast.  What’s more, many experts now recommend exercising in a fasted state as the workouts are more intense (with the increased adrenaline) and the gains are better (with the increased growth hormone).


Eating three meals a day is simply not a requirement for good health.  Hippocrates in 400 B.C. advised eating a high-fat diet and only once a day.  How did he know?  Fasting is instinctual.  Humans, like all animals, avoid food when ill.  Consider this quote:

“A little starvation can really do more for the average sick man than can the best medicines and the best doctors.” - Mark Twain


We needed keen senses and mental faculties during the Paleolithic times to find food during periods of starvation.  If our senses didn’t sharpen and we just became lethargic, the human species would have died off.


Several myths about fasting:

1.    It puts you into “starvation mode.”

Calorie-restricted diets cause a 25 to 30 percent drop in basal metabolic rate in most patients.  Another problem with calorie-restricted diets is that most people feel cold, tired and less energetic, and this makes sense with a lower BMR (the number of calories burned in 24 hours at rest).  This drop in BMR is part of the reason calorie-restricted diets almost always fail.  As soon as the patient gives up, the BMR is still low (starvation mode), and when the normal pre-diet calorie intake resumes, the person is burning even less than before, so the weight comes back, and then some.  Fasting, on the other hand, raises BMR.  You go from burning sugar to burning fat after a few days.  Let’s face it, fat isn’t there to look good; it must serve a purpose, and that purpose is fuel.  But, how many of us ever get to tap into that giant fuel tanker of fat we all have?  Almost none of us.

2.    Fasting burns muscle.

This only happens when body fat drops below four percent.  The average elite male marathoner has about eight percent body fat, and we know what he looks like.  A study of every-other-day fasting demonstrated that after 70 days of alternate-day fasting, there was no change in muscle.  All weight lost was fat.  We all normally break down about 75 grams of protein per day with variability depending on activity.  Remember that our fuel sources are glycogen (glucose) and fat (ketones and fatty acids) - that’s it.  Protein should never become a source of fuel, and it doesn’t when fasting properly.  In addition, the heightened growth hormone response to fasting is a stimulus to muscle building, which is again why so many elite athletes work out when fasted as gains are greater.

3.    Fasting causes low blood sugar.

Once there is no longer food in our stomach fueling us with sugar, the body taps into glycogen.  Glycogen is depleted about 24 to 36 hours into a fast (there are about 2,000 calories of sugar stored as glycogen).  Next, gluconeogenesis (which literally means making new sugar) takes over, and this uses the glycerol backbone from stored fat to make sugar so that levels of sugar during a fast never drop too low.

4.    Fasting results in overeating.

If you fast for one day and eat the next, it is true that calorie intake will increase from about 2,400 to 2,900, for instance.  But if you would normally eat 2,400 calories two days in a row (4,800 total) and you’re eating a little more (2,900) every other day, you’re still net negative by 1,900 calories every two days.

5.    Fasting deprives the body of nutrients.

For short periods of fasting (intermittent, 24-, 36-, or 42-hour fasts), there is no need to worry.  For longer fasts, taking a daily multivitamin is important.  There are essential fatty acids and essential amino acids that we all must get with longer periods of fasting, which is why bone broth at “dinnertime” during a fast is critical.  There are NO ESSENTIAL CARBS in life!  If you follow a low-carb diet, you’ll get extra essential amino acids and fatty acids.

6.    “It’s crazy!”

The science is clear.  Some of us and many of our patients aren’t going to let the facts confuse us.  


What does fasting do for us?

1.    Improves mental clarity and concentration

2.    Assists with weight and fat loss

3.    Decreases blood sugar (which makes it one of the best treatments for type 2 diabetics)

4.    Improves insulin sensitivity and lowers insulin

5.    Increases energy

6.    Increases fat burning

7.    Prevents Alzheimer’s

8.    Extends life

9.    Reverses aging

10. Decreases inflammation (the root cause of all age-related illnesses)


Why do it?

1.    Diets fail.

2.    A low-carb, high-fat diet is great if you can follow it, but the key is IF.

3.    It’s free.

4.    It’s convenient.  Most Americans are now consuming 50 percent of their meals out of the house.

5.    This will allow you to cheat without guilt and to enjoy life’s pleasures.  You plan fast days around special occasions or weekends out with friends.


7.    It works with any diet.


More on fat storage…when glycogen supply in the liver drops, we start to get hungry.  If food is available or if glycogen is available, we will not burn fat.  As I mentioned, we only have about 2,000 calories of glycogen/sugar stored.  How many calories of fat do we have stored?  Let me give you two examples:

1.    Patient weighs 150 pounds with nine percent body fat, so 150x0.09=13.5 pounds of fat=47,250 calories of stored fat.  Wow!!

2.    Patient weighs 180 pounds with 40 percent body fat, so 180x0.4=72 pounds of fat=252,000 calories of stored fat.  OMG!!  Still think a patient is going to starve to death fasting with 252,000 calories of fat stored?  Unlikely!  The key is getting access to that fuel tanker with a one-gallon gas tank (our 2,000 calories of glycogen) which many keep filling up constantly by eating low fat.


Other interesting fasting facts:

1.    When fasting, organ size drops (the fatty liver will disappear).  The only two organs that remain the same size during a fast are the brain and the testicles.  The brain is actually boosted during fasting, and this is evident in many trials and in stories from American POWs during the war who were imprisoned in Japan.  They mention astonishing mental clarity after two days of fasting.  Some were able to memorize entire books.  Others stated that they learned a new language in weeks.  This is the opposite of “food coma.”

2.    Rats that were put into a program of IF (intermittent fasting) had an increase in motor coordination, cognition, learning and memory.  Don’t ask me how the researchers figured this out.  There was also less rapid aging and less age-related deterioration of neurons with fewer symptoms of Alzheimer’s and Parkinson’s.

3.    This held true for humans as well with increased memory, synaptic formation and electrical activity.  The explanation relates to higher levels of BDNF, the growth hormone for new brain cells, which increases significantly during fasting.  Levels of insulin correlate INVERSELY with memory.  I test insulin levels on all of my patients through CHL.  For those of you who want to add this, the CHL range is 1 to 24.  In my opinion, however, normal insulin is under 9; perfect is below 5.

4.    Autophagy (self-eating, literally) is the process whereby old organelles inside cells are cleaned out and replaced.  It is very important to clean out cellular debris and worn out organelles as buildup of these is exactly what causes degenerative diseases.  So, we want to increase autophagy.  High insulin, high glucose and high protein intake all turn off autophagy (not good).  Even as little as three grams of Leucine (the amino acid) turn off autophagy.  Protein in excess (which doesn’t take much) stimulates mTOR, our master food and energy sensor, and this turns autophagy off and cellular debris builds.  When mTOR is not being triggered and the body senses a lack of resources (as occurs during fasting and limitation of protein), the body prioritizes cleaning out old cells rather than trying to replace them as there aren’t enough materials available for new cells.  The best trigger for autophagy is fasting.

5.    Alzheimer’s disease is a buildup of cellular debris in the brain, specifically AB protein.  AB protein is cleaned out during the process of autophagy (the “autophagosome” in brain cells is the garbage truck that engulfs this dangerous debris).  Fasting revs up those garbage trucks.

6.    Fasting also prevents cancer.  What keeps cancers from growing (besides chemo, radiation and surgery)?  Take away their fuel!!  Cancers cannot use fat as fuel; they must use sugar or they can’t grow.  Think about those hot spots on PET scans.  Those are the places in the body HYPERmetabolizing sugar.  Allowing a cancer patient to eat a high-carb diet is not a good idea.

7.    I have never sat across from a sick patient in my office and heard these words: “Doctor, I can’t understand why I have cancer, or heart disease, or Parkinson’s, or Alzheimer’s, or why I can’t lose weight.  I’ve followed a HIGH-FAT, LOW-CARB diet my whole life.”  Everyone with these conditions has eaten the typical American diet - low fat.  This has caused many unintended health consequences and was never based on science.  A low-cholesterol diet is often counterproductive; the body has a set point for cholesterol, and if you drop intake, you will simply produce more.  The difference between a low-cholesterol diet and a high-cholesterol diet for most is three points of total cholesterol on blood tests, and those who eat more fat have much higher HDLs.


Methods of fasting:

Please, please read the book for detail as this has to be done safely.  Special attention must be given to patients on medications.  Underweight patients should never do this.


During a fast, aim for two liters of water daily.  Coffee and tea are permitted and the catechins in green tea act as appetite suppressants to some degree.  Adding heavy cream to coffee (one or two teaspoons) is fine and may help tolerability, but technically it isn’t fasting.  Bone broth near “dinnertime,” especially for longer fasts, can be very helpful.  It has anti-inflammatory properties.


Types of fasts:

Shorter fasts (less than 24 hours) are good for weight loss.  Longer fasts (>24 hours) are not only good for weight loss, but also for reversal of diabetes, fatty liver and many metabolic diseases.


Short fasts:

16-hour fast - Eating is done within an eight-hour window every day.  Typically the first meal of the day is skipped and people will eat all of their meals between 11 am and 7 pm.  This type of intermittent fasting works best with a high-fat, low-carb diet.


20-hour fast - All calories are consumed within a four-hour window.  This is the so-called “Warrior Diet.”


Of interest, insulin levels will rise more at 7 pm than they will from exactly the same meal consumed earlier in the day.  The advantage of the Mediterranean Diet and the reason in part for its success lie in the fact that the largest meal of the day is consumed midday, not at night.  This keeps insulin lower, so weight gain is less.  Similarly, ghrelin, the hunger hormone, peaks at night and is lowest in the morning.  This is why we tend to be least hungry in the morning.  Ghrelin peaks during the first two days of fasting (the second day is supposed to be pretty rough in terms of hunger) but then plummets day three, and those on long-term fasts describe the disappearance of hunger on day three.


Long fasts:

24-hour fasts - This is essentially eating one meal a day, and you run little risk of nutrient depletion.  You must be careful to choose healthy foods for that one meal to keep up the essential fatty acids and amino acids.


5:2 plan - This is an easier method of fasting and involves eating “normally” (hopefully high-fat, low-carb) for five days a week and then restricting calories to 500 daily for women and 600 daily for men on the other two days.  While this is technically not fasting, the calorie intake is low enough to allow benefits and isn’t as difficult as no food.


Alternate-day fasting - This is similar to the 5:2 plan but involves eating normally one day and then 500-600 calories the next day.  It’s a bit more intense than the 5:2 plan.


36-hour fasts - Commonly used to reverse type 2 diabetes, this involves eating the final meal at 7 pm, for instance, and then skipping an entire day of eating.  The next meal would be at 7 am two days later.  This is usually sustained for months and, if adhered to, has the power to eliminate all diabetes medications.  It is critical to monitor blood sugar three to four times a day and to not use insulin during the fast period.  Cutting down other diabetic meds is an art as well, and hypoglycemia is a significant concern if medications aren’t properly cut back.  This is usually performed three times a week and is one of the more popular regimens in the Intensive Dietary Management Program run by the author of this book.


42-hour fasts – It follows the same as pattern as the 36-hour fast but involves skipping breakfast and beginning at lunch.


Extended fasts (anything longer than 42 hours):

The typical fast would be one to two weeks.  By the end of two weeks in the studies documented, most cases of diabetes were reversed.  The average weight loss was 17 to 18 pounds.  The longest fast ever recorded with just water, a multivitamin, a few supplements but NO FOOD was 382 days.  The patient was 456 pounds at the start and weighed a healthy 180 pounds at the end.  He was monitored carefully and never had hypoglycemia.


The first two days are tough, especially the second day, but then all participants note that the hunger disappears and they could fast for very long periods easily.  There are nuances and important facts about prolonged fasting, such as phosphorous and magnesium depletion and “refeeding syndrome” which relates to phosphorous depletion.  This is extremely rare and can be avoided with careful attention and monitoring.  You must be monitored carefully by a physician.


Fasting tips:

1.    Drink water – lots!

2.    Stay busy.

3.    Drink coffee or green tea as both are appetite suppressants.

4.    Ride the hunger waves.  It won’t be constant.  When it hits, drink coffee or green tea.

5.    Don’t tell anyone you’re doing this.  They will think you’re nuts and try to discourage you.  Remember, the science is clear.  Many people don’t want to let the facts confuse them.

6.    Don’t give up if the first try fails.  Give it a few attempts.  Like exercise, it gets easier.

7.    Follow a nutritious diet on non-fast days.

8.    Don’t binge.  Eat normally on non-fast days.

9.    Don’t change your life to fit your fasting schedule.  Change your fasting schedule to fit your life.


Your Partner in Prevention,


Louis Malinow, M.D.

ASH Certified Hypertension Specialist

Diplomate, American Board of Clinical Lipidology