Monday, December 12, 2011

Fat Is Fuel, Fat Is Good

There are two ways to sustain adequate blood sugar levels.  Because the brain shuts down when deprived of glucose, producing and sustaining blood glucose levels is a primary driver of metabolic processes.  Given the significance of maintaining blood glucose, it would be no surprise that the body has more than one way to get the job done.

That said, how many times have you experienced, or known folks who experienced, hypoglycemia?  This is characterized by feeling droopy, irritable, and hungry - for anything but often especially for carb foods.  Most folks experience this as "reactive hypoglycemia", in which the "victim" eats a large amount of carbs, resulting in a blood sugar spike, to which the body reacts with an insulin surge, after which, blood sugar levels fall too far.

Normally, as blood sugar levels fall, the body compensates by making blood sugar in the liver, and by producing ketones, which allow the brain to use less sugar.  Also, most non-brain cells run well on fatty acids, which is why we store energy as fat.  In short, it should be very hard to achieve "hypoglycemia" in a healthy person.  Strangely, it's so common that folks speak of it often and even plan for a mid morning or mid afternoon snack to avoid the "sugar low light."

The reason for that is that the body has a finite and relatively small capacity for glucose storage, and folks who eat a big dose of carbs are giving themselves a glucose management problem.  The body is equipped for glucose management, but it appears to be the case that when the body has to deal with glucose management problems routinely, it does not sustain the process well.  One reason is that cells will burn sugar inside the cells preferentially, so if the body is always stuffing cells full of sugar, the cells so rarely burn fat for fuel that they begin to maintain very low levels of fax oxidizing enzymes.  In short, repeated high carb intake makes you both sick from the excess sugar, fat, and at the same time, dependent on exogenous sugars as your body's fat burning systems atrophy from lack of use.

Based on the above described cycle, it's no wonder that folks who eat a lot of carbs all the time often get fat - except for the ectomorphs (tall and lean) who seem less capable of using fat for fuel in general.

The question then, is "what do I do about it?"  That's a question we can answer next time.

2 comments:

  1. Great intro and very timely.

    I just posted the details of my self-experimentation in getting a slightly elevated BG level under control: http://myathleticlife.com/2011/12/improved-blood-glucose-control/ (This link is safe for work).

    ...Tim

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  2. Thanks Tim, glad to have you swing by.

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