Tuesday, May 15, 2012

Why We Get Fat: Part 1

The first part of this series will look at the science of how fat tissue is regulated.  Don't be skeered. It ain't that difficult to understand.  

Ever wondered why cutting calories doesn't always help you lose weight?  How about exercising more?  No fried foods or red meat? 

( See how the letters get fatter ?  As they go down the cover?  Get it? ...  get it? )

I recommend you read a book called Why We Get Fat And What To Do About It by Gary Taubes.  
( Resident BDS.  Welcome to the Goody Room )

The message is simple.  We get fat because we eat carbohydrates. Especially carbs that are energy dense or highly refined; breads, pastas, cokes and sweets.  Most of us are accustomed to the "Western Diet" loaded with these types of carbs…and the FDA has long endorsed a food pyramid which recommends that 50 - 60 percent of our daily calories come from carbohydrates.

( Uncle Sam wants YOU!...to fatten up! )

But after reading this book you'll have more to think about than just your waistline.

Why is it so hard to understand the "correct" nutritional paradigm?  For decades doctors, dietitians, nutritionists and the government have all chipped in their two cents…and all the while America became the most obese nation on the planet.  Other cultures that have adopted the Western diet have also experienced increased obesity and at alarmingly quick rates.  After examining the facts it seems likely that the guilty culprit is the carbohydrate and there is some basic, non-controversial science that checks out.     

You've probably heard people talk about why a low-carb diet works.  Your body burns carbs before fat.  This is true but there is a little more to it.  Fat molecules are not just sitting inside fat cells waiting for us to starve or to exercise so that they can be burned for energy. Fat molecules and sugars are constantly flowing through the bloodstream. They are the fuel for our muscle and fat cells. And your body deals with sugars (carbs) before fat molecules in order to keep your blood sugar balanced. It does this primarily with the help of the hormone insulin.

As you eat your pancreas begins to secrete insulin to regulate the spike in your blood sugar due to the carbohydrates.  While dozens of hormones in the body help regulate weight, insulin is the most important when it comes to fat and protein regulation. It controls the activity of two enzymes; LPL and HSL.  LPL ( Lipoprotein Lipase ) is attached to the outside of fat and muscle cells.  It pulls fat molecules and sugars out of the bloodstream and into cells for energy.  An insulin spike from eating carbohydrates increases the activity of LPL on fat cells and inhibits LPL on muscle cells.  If LPL are "instructed" to pull fat into a muscle cell then the muscle will burn it for energy. You get a little leaner.  If LPL pulls fat into fat cells…then that fat will make sweet love with glucose and BOOM.  Triglyceride city.  You get a little fatter.

( Pictures of Science...Hooray! )

Triglycerides are too large to exit the fat cell and must be broken down into individual fatty acids and glycogen to travel back into the bloodstream…which is the job of the second enzyme, HSL or Horomone Sensitive Lipase. (Triglycerides are sometimes formed in the bloodstream too…this is how your doctor can tell your triglyceride "count" by taking a blood sample.  LPL breaks down triglycerides in the bloodstream so that fatty acids can move into cells).  But insulin spikes inhibit HSL from breaking down triglycerides in the fat cell…another process that ensures you are storing more fat than you are burning.  

When LPL is pulling fatty acids into fat cells, and HSL is inhibited from breaking down triglycerides inside fat cells...well, shit son.  That's a double negative process that will either make or keep you Fatty McFatstuff. 

Have you ever eaten a big plate of pasta and bread and then felt lethargic afterwards?  Now you know that eating carbohydrates spikes your insulin, and insulin spikes cause fat molecules to be pulled out of the bloodstream and into fat cells instead of into muscle cells where they would be burned for energy.  No carbs, no insulin spike…and fat molecules are free to flow through the bloodstream to supply energy to your body.  So why have you always heard that carbs give you energy?  Because your body will burn carbs before it burns fat and it does this to keep your blood sugar in balance.  But as soon as those carbs are gone it takes a while to release fat back into the bloodstream for energy.  Crash time.  

Here are some words that I copied from the book and put in parenthesis!

"You'll start secreting Insulin even before you start eating--indeed it's stimulated just by thinking about eating.  This is a Pavlovian response.  In effect, this insulin is preparing your body for the meal you're about to eat.  When you take your first bites, more insulin will be secreted.  And as the glucose from the meal begins flooding the circulation, still more is secreted.  The insulin then signals cells throughout the body to increase the rate at which they're pumping in glucose from the bloodstream.  The cell will burn some of this glucose for immediate energy and store some for later use.  Muscle cells store the glucose in the form of a molecule called "glycogen".  Liver cells store some as glycogen and convert some to fat.  And fat cells store it as fat.  As your blood sugar begins to decrease, insulin levels decrease along with it, more and more of the fat stored during the meal will be released from fat tissue to take up the slack.  Some of this fat began life as carbohydrates and some began life as fat in the diet, but it's indistinguishable once it finds itself stored in the fat cells.  The more time passes after a meal, the more fat you will burn and the less glucose."

This is the basic biological process by which your body deals with fat and carbohydrates.  Once again, at no time has any of this been particularly controversial.  So just imagine if you ate as few carbs as possible…especially the energy dense highly refined ones like coke, candy bars, baked goods, pastas etc?

I know that sounds neither easy nor fun. I believe that people fail in losing weight and eating right for two reasons; lack of education on what to eat and lack of understanding on how to tackle the problem.  Eating "right" or "dieting" to lose weight takes a lot more effort then just laying off certain foods.  You have to do a great deal of planning to set yourself up for success.  As you plan more and educate yourself about eating right… and then witness the results on your own body, it will be easier to change the bad habits that got you where you were to begin with.   

In Part 2 I will go into the foods that you should be eating and why.    

No comments:

Post a Comment