The
world is facing a hunger crisis unlike anything it has seen in more than 50
years.
925
million people are hungry.
Every
day, almost 16,000 children die from hunger-related causes. That's one child
every five seconds.
There
were 1.4 billion people in extreme poverty in 2005. The World Bank estimates
that the spike in global food prices in 2008, followed by the global economic
recession in 2009 and 2010 has pushed between 100-150 million people into
poverty.
Starvation results from the
inadequate intake of nutrients or the inability to metabolize or absorb
nutrients. It can have a number of causes such as prolonged fasting, anorexia,
deprivation, or disease. No matter what the cause, starvation takes about the
same course and consists of three phases. The events of the first two phases
occur even during relatively short periods of fasting or dieting, but the third
phase occurs only in prolonged starvation and can end in death.
During the first phase of starvation,
blood glucose levels are maintained through the production of glucose from
glycogen, proteins, and fats. At first glycogen is broken down into glucose.
However, only enough glycogen is stored in the liver to last a few hours.
Thereafter, blood glucose levels are maintained by the breakdown of proteins
and fats. Fats are decomposed into fatty acids and glycerol. Fatty acids can be
used as a source of energy, especially by skeletal muscle, thus decreasing the
use of glucose by tissues other than the brain. Glycerol can be used to make a
small amount of glucose, but most of the glucose is formed from the amino acids
of proteins. In addition, some amino acids can be used directly for energy.
In the second stage, which can last
for several weeks, fats are the primary energy source. The liver metabolizes
fatty acids into ketone bodies that can be used as a source of energy. After
about a week of fasting, the brain begins to use ketone bodies, as wells as
glucose, for energy. This usage decrease the demand for glucose, and the rate
of protein breakdown diminishes but does not stop. In addition, the proteins
not essential for survival are used first.
The third stage of starvation begins
when the fat reserves are depleted and there is a switch to proteins as the major
energy source. Muscles, the largest source of protein in the body, are rapidly
depleted. At the end of this stage, proteins, essential for cellular functions
are broken down, and cell function degenerates.
In addition to weigh loss, symptoms
of starvation include apathy, listlessness, withdrawal, and increased
susceptibility to infectious disease. Few people die directly from starvation
because they usually die of some infectious disease first. Other signs of
starvation can include changes in hair color, flaky skin, and massive edema in
the abdomen and lower limbs, causing the abdomen to appear bloated.
During the process of starvation, the
ability of the body to consume normal volumes of food also decreases.
Foods high in bulk but low in protein
content often cannot reverse the process of starvation. Intervention involves
feeding the starving person low-bulk food that provides ample proteins and
kilo-calories and is fortified with vitamins and minerals. The process of
starvation also results in dehydration, and dehydration is an important part of
intervention. Even with intervention, a victim may be so affected by disease or
weakness that he cannot recover.
Source: http://www.bread.org/hunger/global/, http://www.mhhe.com/biosci/ap/saladin/digestive/reading5.mhtml
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