Sunday, March 15, 2009
Mark Sisson Is Not Afraid of Fat!
Evolution is all about adaptation – to the environment, to circumstances, to stress and even (or especially) to food. In this context of adaptation, it’s truly amazing how “inventive” the human body has become in finding novel (and perhaps heretofore uncontemplated) ways to repair damage we do to ourselves through our diets and other lifestyle indiscretions. And most of these changes are less than a few hundred years old, which makes the adaptations even more remarkable.
Let’s use cholesterol as an example. Cholesterol is actually very beneficial. Among other duties, it’s a necessary component of every cell membrane and it’s involved in hormone production. The body makes about 1400 mg a day just to keep up!
Now let’s take a stressful lifestyle (show of hands, please), add in a bad diet and lack of exercise and we get an inflammatory process in the arteries that causes lesions. This inflammation problem is completely unrelated to amounts or types of cholesterol.
Nevertheless, the ever-inventive human body adapts to this inflammation sequence by using cholesterol as a band-aid to cover up the lesions until healing can take place – which, of course, almost never happens since the silly human continues to live the same pro-inflammatory lifestyle. Eventually, the cholesterol band-aids harden (sclerosis), narrow the arteries and sometimes break off causing a heart attack.
Of course, we blame the cholesterol for all this and embark on a national campaign to rid the body of this important substance instead of focusing on the foods (and other stresses) that promote inflammation in the first place!
Now let’s consider fat. For years we believed fat was nothing more than nature’s way of storing extra calories for some future famine. That would be a handy little adaptation in and of itself if that’s all it were. But when you do the math, you see that it doesn’t require a lot of fat to survive or even migrate for long periods. A 165-pound person with only 13% body fat has 21.45 pounds of fat. Being generous and assuming that you need a minimum 3% just to carry on basic survival functions, that leaves 10% or 16.5 pounds of fat to live off. At 3500 calories per pound of fat and 100 calories per mile walking, you’d theoretically have enough fat to survive weeks and migrate several hundred miles.
So maybe fat has another purpose, and this is where my friend Art De Vany’s description of fat as a toxic waste site (my words) comes in. Modern humans have so thoroughly altered foods to focus on simple carbohydrates (sugars) that we now consume hundreds of excess grams of it every day.
As Art has explained, the body recognizes excess sugar (glucose) as a toxic load – and remember, it doesn’t take a whole lot of it to be excessive – and the body starts the adaptive process of secreting insulin to take sugar out of the bloodstream and deposit it into the muscles.
Two problems arise immediately:
First, there’s not a lot of room in those muscles. Ask any athlete who’s ever tried to carbo-load for an event. Secondly, most people aren’t athletes and have lost significant utility of their muscle through atrophy, further diminishing storage. Furthermore, they don’t burn off the already-stored glycogen because they don’t exercise.
But here’s where the body has become so elegantly adaptive once again. It creates little storage facilities in the form of additional fat cells. Not because it’s trying to store calories for some future famine, as modern medicine might have you believe, but because it’s trying to find novel and effective ways to rid the body of this very toxic glucose excess.
And it’s a pretty good solution. Insulin allows glucose access to these fat cells which grow larger and more numerous over time. Problem is, it’s always one step behind, so the fat cells fill up just as the muscle filled up, leaving excess glucose in the bloodstream after the next high carb or high calorie meal until more fat cells can be made.
And so the spiral continues as 40 million Americans are headed towards type 2 diabetes.