First, a few words on energy. By energy we mean the ability to do work. So
that's what your husband been needing all this time, you say. Hold on a minute,
please, we're not covering that question today. The ability to do work may take any
of three forms: mechanical, electrical, or chemical. But apart from these three forms,
energy can also be stored as "potential energy" or put to work as "kinetic energy."
One example of the former is the hydraulic energy latent in a water reservoir. Open up
the floodgates, and the stored energy will be converted into working energy. But let's turn
to a more engaging subject, one you're no doubt just a little curious about. Besides, it's
much more exciting to talk about fat cells than boring water reservoirs.
Potential energy in chemical form can be found in the fat stored in our body
tissues. In many men and women, these fat deposits go too far and appear
as unsightly bulges. The question is how to open the floodgates of these fat deposits.
I'll tell you how. First, let's see how fuel from nutrients is distributed in the body. The
person we have in mind slaked his appetite a couple of hours ago at the lunch table.
The nutrients, having received their own energy from the sun, have already been broken
down in his stomach, and the fuel is located in his liver. Because this person prefers to
spend his late afternoons in sedentary pursuits, the power plants in his muscles are only
working at twenty to thirty percent capacity.
Truck convoys shuttle in shifts from the liver to the muscle cells and back again.
One convoy is loaded with fatty acids, the other with glucose. But when these
heavy-duty trucks arrive to unload at the cellular power plants, they find the gates shut.
The foreman explains to them curtly that there's no need for all the fuel since the owner is
only using his muscles at normal strength. All the same, he lets a few of the trucks past the
gate, but only the ones loaded with glucose. He directs them to a special warehouse on
the cell grounds where the glucose can be temporarily stockpiled.
These warehouses are called glycogen reserves. They are extremely important for
people in endurance sports. They are only used to store digested carbohydrates - e.g.
spaghetti or potatoes - in the form of glucose. (When I use the word "sugar" or glucose, I
don't mean processed sugarbut rather a quite specific sugar molecule called dextrose,
into which the compound molecular sugar chains in spaghetti and potatoes are broken
down during digestion. You can find more information on this subject in the chapter on
nutrition.) Nature installed these glycogen tanks in our muscle cells because carbohydrates,
or rather glucose, are our bodies' gasoline. Fats are important suppliers of energy, too, but
more in the form of stockpiled energy. This is why the trucks carrying the loads of fat were
turned away at the cell gate.
Now they have to find places in the tissue to unload. And they soon do - in those
all-too familiar parts of our bodies. Here the fats are temporarily stored until,
one day, the foreman requests them from the warehouse. But before he does, the
power plants have to be working at one hundred percent capacity. This requires more than
a walk after lunch. In all fairness, I should also mention that fats serve many useful functions
in the body. They help to build up the cell membrane, for example, and subcutaneous fatty
tissueinsulates us against cold and heat. Even slender people always have sufficient energy
reserves in their fat deposits, so there's no need to force-feed the fat cells. It follows that fat
people carry an impressive amount of potential energy in their bulges. In short, they are
loaded with energy.