METABOLISM, HORMONES AND FAT LOSS
Human metabolism can be defined as all the chemical processes in the body that
make it possible for cells to continue living. At any given moment inside
our bodies there may be hundreds and even thousands of chemical reactions
taking place, and the majority of these are concerned with making the
energy in the foods we eat available to the various cells which make up
tissues, organs and systems.
by Eva Urbaniak, N.D.
For example, energy is required for muscle contractions, secretions by
the glands, absorption of foods from the gastrointestinal tract, the life
processes of all our cells, and virtually all the functions of our bodies.
Many of these reactions could not take place without the aid of enzymes,
co-enzymes or vitamins, and hormones. Often in the body, the cascade of
events starts with a hormone being secreted from an endocrine gland, which
usually operates on a negative feedback system, the hormone activates
the enzyme and the chemical reaction takes place. An example of this is
the hormone insulin, which is associated with glucose transport into the
cells. Insulin assists glucose into the cells for utilization. In the
case of late onset diabetes mellitus, often associated with obesity, the
cells that produce insulin in the pancreas, called the B-cells of the
Islets of Langerhans, are less responsive or non-responsive to elevated
blood glucose, and the insulin receptors in the cells throughout the body
either decrease or become less responsive. It is the goal of insulin therapy
to force the receptors to respond, when in fact treating the obesity with
dietary control, works as well if not better, since the predisposition
is being treated or the underlying cause is being addressed. Since we
have already mentioned obesity, let's just briefly define it. Obesity
simple means deposition of excess fat in the body, caused usually by ingestion
of greater amounts of food than can be utilized by the body for energy.
The excess food, whether consisting of fats, carbohydrates, or proteins,
is then stored as fat in the adipose tissue to be used later for energy.
At least seven hormones secreted by the endocrine glands have marked effects
on fat utilization. A quick review of the principal endocrine glands of
Pineal and pituitary, thyroid, parathyroid, thymus, pancreas, islets of
Langerhans, adrenal glands, ovaries and testes.
Probably the most dramatic increase that occurs in fat utilization
is that observed during heavy exercise.This results almost entirely
from release of epinephrine and norepinephrine by the adrenal medullae
during exercise. These two hormones directly activate hormone sensitive
triglyceride lipase, an enzyme that is present in abundance in the
fat cells and this cause very rapid breakdown of triglycerides and mobilization
of fatty acids. Sometimes free fatty acid concentration in the blood
rises as much as eightfold and utilization of these fatty acids for energy
correspondingly increases. The stress of exercise and other forms of stress
causes large quantities of corticotropin hormone to be released by the
anterior pituitary causing the adrenal cortex to secrete glucocorticoids,
which also activate the same lipase and other lipases as well. Growth
hormone secreted by the anterior pituitary also activates lipase,
but also increases metabolic rate and in fact, in contrast to other hormones,
it does not function through a target gland, but instead exerts its effects
on almost all or all tissues of the body. More studies are currently being
done on growth hormone as there are implications as an anti-aging factor.
Under its influence, fat is utilized for energy preferentially to carbohydrates
or proteins. Strenuous exercise and the first few hours of deep sleep
cause spikes in growth hormone.
Finally, thyroid hormone causes an overall increase in the rate of energy
metabolism of all cells, and rapid mobilization of fat and carbohydrates.
This short overview of hormones and regulation of body functions illustrates
the importance of seeing your doctor before undertaking major changes
in lifestyle or weight loss greater than twenty pounds. Your doctor can
evaluate your condition more objectively than you can and can order any
necessary tests to rule out any hormonal problems.
The treatment of obesity depends simply on decreasing energy
input below energy expenditure. Once the weight loss has occurred, as
long as energy expenditure exceeds energy input, the weight can usually
be maintained. To some this can be the equivalent of starvation. To lose
weight, a person's diet should include large quantities of bulk, (vegetables
and fruits, with the skins, if they are edible) which in general is made
up of non-nutritive cellulose substances. (Psyllium seed, guar gum, pectin,
as in Metamucil and other fiber supplements) Bulk fiber can make a person
feel full if taken before meals, so the tendency is to eat less. Increasing
the drinking of water between meals can also give a person a feeling of
fullness and is refreshing and detoxifying, and could help prevent that
trip to the candy machine or the latte stand. If a person drastically
reduces the amount of food intake, it is important to supplement with
vitamins. It only takes one or two weeks for a vitamin deficiency to become
apparent. Vitamin deficiency can cause debility and can even lead to death.
That is why we have guidelines like the RDA, the required daily allowance,
so that if a person maintains a diet that does not provide these nutrients,
a vitamin supplement can provide the nutrient insurance necessary to prevent
Drug therapy in the treatment of obesity in the past consisted of amphetamine
drugs, which although they did inhibit the feeding centers in the hypothalamus,
they also overexcited the central nervous system, making a person nervous
and irritable, elevated blood pressure, and in fact, adaptation to the
drug occurred so that weight loss was usually no greater than 10%.
Today, newer drugs are prescribed with an eating and exercise
plan. It makes one wonder if in the studies of these drugs, if there was
a control group that did JUST the eating and exercise plan without even
a placebo, and if they lost weight as well.
So the bottom line is, physical activity can bring about changes in the
levels of hormones, which regulate fat-burning and consequently, fat and
weight loss; and a healthy diet with lots of fruits and vegetables, adequate
protein, and a minimum of eight 8-oz glasses of water per day can guarantee
successful weight loss and maintenance. If a person fills up on the bulk-containing
foods during a meal, there is a feeling of fullness, which can prevent
over-eating of other foods. So fill up on vegetables and fruits!
These activity and dietary suggestions have been proven, and just need
to be incorporated into a person's lifestyle and implemented to be effective.
Most importantly, food intake in humans is controlled as much by habit
as it is by hunger. Sometimes, habitual eating (or compulsive or mindless
eating) is used as a coping mechanism for many, but this is self-defeating
behavior, and falls more into the realm of the psychology of weight loss,
which is actually material for another article.
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