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Nutritional Influences on
Muscular Development and Fat Metabolism
by J.E. Grogan
for Show Feeds, Inc.™
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Thyroid
Hormones:
The thyroid plays a major role in controlling energy expenditure and
determining the basal metabolic rate (BMR) - the resting rate at
which calories are burned for energy. The thyroid hormones divert
calories away from storage as fat so they are more easily used for
energy. The thyroid is also critically important for the liberation
and metabolism of stored fat.
As in many
"activating" processes, one thyroid hormone is a catalyst for the
other. Thyroxine (T4), the thyroid hormone released into the blood,
is converted to triiodothyronine (T3) - the active thyroid hormone.
T3 is the hormone that strongly activates fat metabolism.
The
thyroid requires more than just iodine to function optimally. The
vitamins A, B-2, C,E; the minerals potassium, magnesium, copper,
zinc; the amino acid tyrosine; and possibly the trace element
rubidium are all involved in healthy thyroid function.
It is also
well known that carbohydrates can stimulate the conversion of T-4 to
T-3. If the carbohydrate content of the diet is too low this
conversion can be depressed.
The
activation of thyroid hormone production is also dependent on the
activity of a healthy pituitary gland. The anterior pituitary
releases the hormone TSH to stimulate thyroid hormone synthesis.
Inadequate thyroid function can also depress liver function where a
large part of fat metabolism is activated.
Optimal
thyroid function and it's fat mobilizing effects are dependent on a
precise balance of a variety of factors. An over stimulation of
thyroid activity can actually decrease lean muscle mass and cause a
breakdown of body protein. This can rapidly deplete nutritional
reserves and cause a major drop in overall health status.
Insulin:
Insulin is a hormone produced by the beta cells of the islets of
langerhans in the pancreas. Insulin's chief functions are the
regulation of carbohydrate and fat metabolism and the stimulation of
amino acid and sugar uptake by the cells.
By
increasing the transport of sugar into the cells blood, sugar tends
to drop. This increases the formation of glycogen or stored sugar in
the muscles. Insulin also increases cellular uptake of amino acids.
This increases protein synthesis and minimizes the use of amino
acids for energy production; which is very inefficient
metabolically. Insulin, by increasing amino acid uptake inhibits the
breakdown of lean muscle mass and helps to maintain the integrity of
the body's chief calorie burning tissue, which is muscle tissue.
Insulin can enhance functional thyroid status which can increase fat
burning capabilities through the thyroid hormone T-3.
For
optimal benefits insulin should stay in a very narrow range or level
in the blood. Insulin as important as it is for sugar and amino acid
uptake by the cells is a two-edged metabolic sword in any fat
burning or metabolizing program. Healthy levels of insulin stabilize
lean mass (muscle) and minimize fat production (lipogenesis).
However, an overabundance of/or an over stimulation of insulin
release can increase fat production markedly and very quickly. This
results in a lowered lean to fat ratio because of the increase in
body fat.
Stabilizing carbohydrates in the diet with adequate high quality
proteins and fatty acids minimize the risks of an over release of
insulin and it's subsequent fat producing properties. (this is
especially important in non-ruminants).
Also, the
use of nutrient insulin potentiators can minimize cellular over
exposures to insulin to protect lean mass and minimize fat
production.
Even
though fat cells cannot be converted to muscle, their component
fatty acids can be utilized for energy purposes and the fat cell
itself can shrink to extremely low volumes. In part, the benefits of
nutrition insulin potentiators activate these fat burning,
fat-shrinking properties.
Growth
Hormone:
Growth hormone (GH) or somatotropin is one of the best publicized
muscle builders and fat burners. Growth hormone promotes the growth
of cells and tissues by stimulating protein synthesis due to:
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Increased amino acid transport into the cells.
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Stimulation of RNA synthesis.
It also
stimulates the release of fat for the production of energy. GH has
the ability to increase the rate of fat breakdown (lipolysis) and
inhibit the formation of new fat (lipogenesis). Growth hormone is
formed in and released from the anterior pituitary. Physical
exercise, sleep, caloric restriction, low blood sugar and certain
amino acids can stimulate the release of growth hormone.
Growth
hormone's primary synergists are insulin, testosterone and the
minerals magnesium, zinc and potassium. The primary antagonist to
growth hormone is the stress hormone cortisol produced by the
adrenals in response to any physiologically stressful event.
Since GH
is released by the anterior pituitary - healthy pituitary function
is prerequisite to optimal GH release. Adequate high biological
dietary proteins, stabilized carbohydrates, essential fatty acids
and activated nutritional cofactors, including protected amino
acids, glandular protein materials and certain phyto compounds can
help achieve optimal GH release and its muscle building and fat
burning qualities by contributing to the overall health of the
pituitary.
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