The Affects of Bodily Stress on Metabolism
The body reacts to accidental stress such as from an accident
which causes bodily harm or from a medical procedure much the same way it reacts
to the stress of starvation – with one major difference. When the human body
suffers from starvation, whether intentionally or un-intentionally, the body's
metabolism begins to slow down becoming hypometabolic. When severe stress
strikes the body's metabolism rises dramatically, becoming hypermetabolic.
There are two phases to the body's response to stress: ebb phase and flow phase.
During the early or ebb phase of stress, which begins immediately after a bodily
injury, the identifying symptoms include decreased oxygen consumption,
hypothermia (lowered body temperature), and general lethargy. After a serious
injury or medical procedure such as surgery the main concern for the first 36 to
48 hours is to maintain the cardiovascular system and keep blood and oxygen
flowing to all areas of the body.
After the initial 36 to 48 hours have passed the body begins the recovery or
flow phase in which the metabolism begins to increase. This flow phase is
characterized by increased oxygen consumption, hyperthermia (increased body
temperature), and increased nitrogen excretion, as well as expedited catabolism
of carbohydrate, protein, and triglycerides to meet the increased metabolic
demands. This increase in metabolism while the body heals itself will last for
days, weeks, or months depending on how long it takes to heal.
The more stresses the body has to deal with the greater the catabolism and loss
of proteins it will experience. As an example a person having an elective
surgery will encounter a number of metabolic stresses. Before their surgery most
people are allowed only clear liquids and in some cases nothing by mouth. After
their surgery they will not be given any liquids or food by mouth until deemed
appropriate by their doctor. At this point they will be allowed clear liquids
then progress to full liquid diets until they are able to eat regular food.
If this same patient is suffering from poor nutrition before their surgery they
are at a greater risk to get pneumonia or a wound infection along with a fever
because of their decreased protein synthesis. Much like during starvation the
body will begin to turn to it own internal stores to meet its energy demands.
The body will begin to cannibalize its own muscles and as these are depleted the
body's immune system will begin to falter leading to an increased risk of
infection.
The nutrients that are affected by hypermetabolic stress include proteins,
vitamins and minerals, as well as related nutritional concerns for total energy
and fluid intake. During moderate metabolic stress protein requirements are
reported to increase from 0.8gm/kg of body weight to 1.0 to 1.5 gm/kg of body
weight. For more severe stress protein requirements can increase to 1.5 to 2.0
gm/kg of body weight. These levels are needed to provide the energy needed for
optimal protein synthesis.
The need for vitamins and minerals also increases during times of bodily stress.
Body tissue repair depends on adequate amounts of vitamin C, zinc, calcium,
magnesium, manganese and copper. At the very least the recommended daily amounts
of these vitamins and minerals must be consumed during times of stress brought
about by bodily injury. It is best to get these nutrients through the foods
eaten to makes sure that enough calories are being consumed to help fuel the
body's healing process.
The body is a complex machine that needs adequate calories and nutrients to
function. This is doubly true during times of stress when the need for adequate
nutrition will help the body heal quickly.
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