There are only 2 states your body can be in at one time:  fed or fasted.  In fact, you are in one of those states right now!  Even if you are a typical American who eats breakfast, lunch, and dinner (with snacks in between, because we have been told that the more meals we eat, the faster our metabolisms will run), you wake up each morning in a fasted state.  The first meal of the day is called break-fast, because it’s then that you break the nightly fast.  So—congratulations!  You are already fasting EVERY SINGLE DAY OF YOUR LIFE.  Fasting doesn’t sound quite so odd when you think of it that way, does it?  You’re already a faster, and you didn’t know it! So, now that we have determined that you ALREADY fast every single day, it’s just a matter of extending the fast (unless you wake up at night to eat every few hours, in which case you are eating like a newborn...who specifically eats that way to gain body size...think about it.)  I’m pretty sure you don’t wake up at night to eat, so we have confirmed that your body already knows how to fast. But WHY should we fast?  Ahh, that is the best part.  Fasting gives us a metabolic advantage that other weight loss programs are missing. Remember from the “calories” chapter—when our bodies perceive that we are in a caloric deficit, our metabolisms slow to protect us.  We saw that in the Biggest Loser study.  The key to making any weight loss plan work for us is in keeping our bodies from perceiving that we are in a caloric deficit.  That is where the magic of fasting comes in. When your body becomes adapted to fasting (and you don’t spike insulin during the fast; more about how to do that in the Keeping the fast chapter), you become a fat burning machine during the fast.  Your body finally taps into your fat stores, and the energy you have stored on your body can power you throughout the day.  That is what it is stored there for, after all! Here is how the magic happens:  because you have PLENTY of stored energy right there on your body, AND you can finally access it efficiently, your body does not get the signal that you are in an energy deficit.  This is BIG NEWS, people!  Your metabolism does not slow, as the Biggest Losers’ metabolisms slowed.  So what is “resting energy expenditure”?  It’s how much energy your body burns while at rest.  Don’t let the word “starvation” scare you, though. When you are fasting, you aren’t in danger of starvation.  With an intermittent fasting schedule, you are only fasting “intermittently.”  It’s in the name of it, after all. In the conclusion of that study, the authors state, “Resting energy expenditure increases in early starvation, accompanied by an increase in plasma norepinephrine. This increase in norepinephrine seems to be due to a decline in serum glucose and may be the initial signal for metabolic changes in early starvation.”  Because of the fasting, resting energy expenditure went up, rather than down. Besides increasing resting energy expenditure, intermittent fasting has other health benefits, which are being explored by the medical research community. From the article:  “As detailed in the remainder of this article, findings from well-controlled investigations in experimental animals, and emerging findings from human studies, indicate that different forms of fasting may provide effective strategies to reduce weight, delay aging, and optimize health.”  The authors go on to provide specific benefits from various research studies:  the research they summarize has shown that fasting increases cognitive function, is anti-aging, may protect against cancer and various neurological diseases, and reduces inflammation. Yes, this is an exciting time for research related to intermittent fasting!  In fact, the 2016 Nobel Prize in Medicine was awarded to Yoshinori Ohsumi for his research related to a process called “autophagy. What is autophagy?  It is a process that occurs naturally within your own body.  It’s how your body breaks down excess cellular “junk.” As an oversimplification, think of it as your body’s own recycling system, and it’s how your cells take out the garbage.  Why do we need autophagy to happen?  Over-accumulation of cellular “garbage” is responsible for various diseases or conditions related to aging.  If you don’t give your body a chance to clean out the garbage, it gunks up the whole system.  Think about how this would look in your own household.  If you stopped taking out the garbage, things would get out of control very quickly.  Our bodies rely on the process of autophagy to maintain our healthy state.  From the linked website, above:  “Disrupted autophagy has been linked to Parkinson's disease, type 2 diabetes and other disorders that appear in the elderly. Mutations in autophagy genes can cause genetic disease. Disturbances in the autophagic machinery have also been linked to cancer.”  Whoa!  As you can see, taking out the “cellular garbage” is pretty important! What stimulates autophagy?  If you guessed FASTING, then you are correct! Autophagy has one other exciting benefit for those of us who are losing weight through intermittent fasting.  Remember—during autophagy, your body is taking out the cellular garbage.  As we lose weight through fasting, our bodies “eat up” the excess proteins hanging around in various places, and that can include excess skin.  When people lose fat following a traditional low calorie diet plan (where they don’t get the benefits of autophagy), they can be left with saggy skin.  You may have seen photos of people who have experienced extreme weight loss, and they are often left with so much excess skin that they need to have surgery to correct the problem.  Dr. Fung (author of The Obesity Code and the Intensive Dietary Management blog) has worked with many patients in his medical practice, and he uses intermittent fasting to help them lose tremendous amounts of weight.  He reports that his patients, who experience autophagy (thanks to fasting), don’t have the problem of excess skin, even after losing in excess of 100 pounds.  How exciting is that? So—in this chapter, we have learned that we already fast every day, short term fasting has been shown to rev up our metabolisms, and research on fasting shows many amazing health benefits. Instead of worrying that fasting is extreme or dangerous, we see that it’s incredibly beneficial and on the cutting-edge of medical research. Now that you know WHY you should fast, it’s time to learn HOW!
NOTE:  Since fasting has so many health benefits, you may be wondering if there is anyone who should not adopt a fasting lifestyle. It’s important to know that fasting is NOT appropriate for children or pregnant women. Fasting is also not appropriate for anyone who has been diagnosed with an eating disorder.  One important distinction between fasting and an eating disorder:  fasting will not CAUSE you to develop an eating disorder, which is a psychological condition; but, if you suffer from an eating disorder, fasting can exacerbate it. In addition, if you have any health conditions, you should consult a medical professional before beginning a fasting regimen. And again—you should not take medical advice from me.  You should always consult your doctor if you are in doubt.