I am going to summarize what I have learned about how the body works.  Remember that I am not a medical doctor or a nutritionist, and keep that in mind as you read.  Also remember that nothing I am discussing should be considered to be specific medical advice from me to you.  There are fantastic books written by actual medical doctors and experts in the field (see the Annotated Bibliography, located in Appendix C, for my recommendations) that you can (and should) refer to in order to learn more about these topics.  I am going to hit the highlights so that you have a basic understanding of what is going on in our bodies.  Perhaps my analogies or explanations will be over-simplified in places; remember, I am an elementary teacher, so I spend my whole day simplifying complex things so that young kids will understand them. Now, for some science. Conventional diet advice tells you that you have to restrict calories to lose weight.  Everyone knows this.  As I mentioned in the last chapter, it is simple:  you must burn more energy than you take in if you want to lose weight. Scientists have figured out a way to measure the amount of energy in various foods in a lab, and they call the energy “calories.”  Back in the day, our great-grandparents didn’t know what calories were.  Somehow, they were able to eat appropriate amounts of food, and it was rare to see an obese person back then.  How did they do it without counting calories, when they didn’t even know what calories were? By now, though, we’ve all heard of calories, and most of us have tried to count them at one time or another.  Scientists have shown that the calorie calculations of various foods are consistent over time....in a lab.  Unfortunately (or fortunately), your body is not a lab.  Think about it:  do you really believe that you could eat 1200 calories of jelly beans and have the same outcome as if you eat 1200 calories of raw vegetables? Spoiler alert:  you can’t.  At least, not long term. The theory that our bodies work like a calorie calculator can be called “calories in/calories out,” and I am going to refer to it using the common abbreviation:  CI/CO.  My very favorite weight loss expert, Dr. Jason Fung, has named it the “Calorie Restriction as Primary” theory, which he refers to as the CRaP theory.  This makes me giggle every time I read it.  I have included his fantastic book, The Obesity Code, in the Annotated Bibliography (located in Appendix C).  He also has a blog at the Intensive Dietary Management website, and I highly recommend it.  I have learned a lot from his book and blog.  Another fantastic book that debunks the CI/CO theory is Good Calories, Bad Calories, by Gary Taub. So, why is CI/CO CRaP when the theory sounds so good and is so widely circulated as the only way to lose weight effectively?  It’s because it doesn’t work for us long term.  You may have tried a calorie counting diet before.  You started counting your calories diligently, you stuck to your plan, and, YES!  You were rewarded with weight loss.  Week after week, your weight went down, until you reached your goal weight.  Once you got to your goal weight, you were able to effortlessly maintain your ideal weight by continuing to count calories, and The End, you lived happily ever after in your goal wardrobe. Is that how it worked for you?  No?  Me, neither.
Why is that?  Let’s take a lesson from the hit television show The Biggest Loser.  In this reality show, the contestants lose truly amazing amounts of weight each week by following the magic formula of CI/CO.  They reduce their “calories in” dramatically, and amp-up their “calories out” through so much physical exertion that they often become physically ill right on television.  Now, that’s entertainment!  For the final episode of the year, the contestants return to reveal their final transformations.  These are truly inspiring stories of people who have worked harder than they have ever worked in their lives to conquer the obesity demons that they have struggled with for so long. They look fantastic, and the audience is inspired. Let me share their dirty little secret with you:  their long-term results are abysmal.  Horrific. Shocking.  The contestants have very little long-term success, and notice that they have never had a reunion show where everyone is slim and fit. This means that their metabolisms had slowed down more than would be expected. This study showed that the period of prolonged calorie restriction—their CI/CO marathon—had an adverse effect that cost the participants 500 calories per day.  They had to eat 500 FEWER CALORIES for their new weights than calculations based on body size alone would predict, just to maintain their new weights. Here is an example of what that would look like in the real world.  If we perform standard metabolic calculations on a hypothetical 5’ 5” 40 year old woman who weighs 125 pounds and is “moderately active”, the calculator tells us that she is supposed to burn about 2036 calories per day, based on size and activity level.  What the Biggest Loser study found is that instead of burning the expected number of calories, the participants’ average metabolic rate was decreased by approximately 500 calories.  In our hypothetical example, that would be a metabolic rate of 1536 calories to maintain her weight (instead of the expected 2036).  Before the show, these contestants had normal metabolic rates, as calculated for their sizes.  As they lost weight, their bodies slowed their metabolisms to compensate.  But after the show, their metabolisms never recovered.  They never again burned the “expected” number of calories for their size. Dr. Fung does a phenomenal job explaining why this happens in his blog at Intensive Dietary Management.  I encourage you to go there and read it.  To simplify it for you here, all you need to really know is that the body did just what it was designed to do.  Metabolic rate slowed down to protect the contestants.  When the body perceives prolonged calorie restriction, it will slow down your metabolism as a protective measure.  Research shows this clearly, as illustrated in the Biggest Loser study. So—are we doomed for failure?  I know that was the tone of all of the news reports that came out after this study was released.  And, if counting calories was the only tool we had for weight loss, then I would agree—why bother, if we are doomed to a life of constant deprivation?  Fortunately, as I said, the body is not a calorie calculator.  Instead, the body works based on hormonal signals and responses that happen behind the scenes.  Instead of worrying about how many calories you are eating, what you really need to worry about is how much insulin your body is releasing during the day.  In the next chapter, you’ll learn about why that is so important.