The Republic of Yemen is under siege, the people are starving to death, and they are running out of time.
By its very definition, starvation is a process. Our bodies are not like vehicles which promptly shut down when they are out of gasoline. Starvation is defined as a severe deficiency in caloric energy intake needed to maintain human life. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and inevitably – death.
What Does The Word Starvation Mean? The answer to this question lies in a series of evolved physiological and metabolic defenses that work to keep a person alive for as long as possible in the event they do not have access to food. Just because a person is starving does not mean they have become helpless. What follows is an explanation of how a person’s body fights to keep them alive and active.
When we experience prolonged low-energy intake and as long as water is available, our bodies enter into a series of metabolic modes. Basically, a person’s body is buying them some time to give them a chance to find some food. Despite the cause, starvation takes about the same course and consists of three phases. The events of the first two phases happen even during fairly short periods of dieting or fasting. The third phase happens only in prolonged starvation and will end in the person’s death.
The First Phase of Starvation:
- During the first stage of starvation, blood glucose levels are maintained through the production of glucose from proteins, glycogen and fats.
- At first, glycogen is broken down into glucose. Only enough glycogen; however, is stored in the person’s liver to last a few hours. After that period of time, blood glucose levels are maintained by the breakdown of fats and proteins.
- Fats are decomposed into glycerol and fatty acids. Fatty acids can be used as a source of energy, particularly by skeletal muscle, thereby decreasing the use of glucose by tissues other than the brain.
- Glycerol may be used to make a small amount of glucose. Some amino acids might be used directly for energy.
The Second Phase of Starvation:
- In the second phase, which might last for several weeks, fats are the main energy source.
- A person’s liver metabolizes fatty acids into ketone bodies that can be used as a source of energy.
- After approximately a week without food, a person’s brain starts to use ketone bodies, as well as glucose, for sources of energy. Proteins not essential for survival are used first.
The Third Phase of Starvation:
- The third phase of starvation starts when a person’s fat reserves are depleted and there is a switch to proteins as the major source of the person’s energy. Muscles, the largest source of protein in the body, are quickly depleted. At the end of this phase, proteins – essential for cellular functions, are broken down and cell function degenerates. Along with loss of weight, symptoms of starvation include:
- Increased susceptibility to disease
- Additional signs of starvation may include flaky skin, changes in hair color and massive edema in the lower limbs and abdomen, causing the person’s abdomen to seem bloated. During the process of starvation, the ability of the human body to consume volumes of food also decreases.
- The process of starvation also results in dehydration and dehydration.
Few people die directly from starvation because they usually die of an infectious disease first.
Starvation and Death:
- Starvation wreaks havoc on a person’s immune system, largely on account of an extreme deficiency of minerals and vitamins.
- Some people will become weak and perish of immune-related diseases during starvation. Eventually, the person’s body will run out of options. Fats, glucose, muscle mass and tissue are finite resources that will eventually be spent and the person will die. The end-stage of starvation usually brings with it one of two different diseases – kwashiorkor and marasmus.
- Marasmus happens due to extreme energy deficiency, often from inadequate amounts of calories and protein. The person’s body weight reaches dangerously low levels and infections are common. Kwashiorkor is a related disease that affects children who are protein-energy deficient and might result in edema and an enlarged and fatty liver, resulting in the distending of the children’s bellies, providing the illusion that children who are starving are well-fed.
- When the person’s death finally arrives, its most immediate cause is by cardiac arrhythmia or a heart attack brought on by either extreme tissue degradation brought about by autophagy, or severe electrolyte imbalances. 
People can die of starvation in as little as three-weeks, or as long as seventy days.
Effects of Starvation:
Starvation affects many systems. Most changes are completely reversible as weight is regained and these include psychological symptoms.
- Metabolic and endocrine effects: these are changes that are adaptive and are about trying to conserve body mass. Growth rate is slowed and puberty will be delayed. Physical activity is often initially reduced but there can be symptoms of hyperactivity in some. Cortisol and insulin secretion are both altered. Muscle starts to brake down to use as an energy source. As starvation precedes losses of electrolytes such as calcium, potassium, sodium and magnesium occur. There will be marked loss of calcium from bones. Overall muscle, liver and gut all shrink very rapidly. Shrinkage in the gastrointestinal tract means feelings of fullness even after only little amounts of food are eaten. Later on kidneys and heart may also lose mass.
- Cardiovascular changes: with weight loss a patient can become bradycardic and arrhythmia’s are sometimes seen particularly where there is low potassium. Cardiac arrest occasionally occurs.
- Low Sodium, low Potassium and sometimes low levels of other elements such as calcium magnesium are sometimes seen.
- Skeletal changes: osteoporosis is frequently seen. Due to lack of calcium and vitamin D particularly. Low oestrogen levels also play a part. There can be growth retardation before full stature is reached. A milder form of bone thinning is osteopaenia. Fractures can occur as a result.
- Body temperature: cold intolerance and very low body temperature or hypothermia can occur.
- Haematological: anaemia can occur adding to weakness and tiredness. White cell counts are also impaired and immune deficiency states can result. Occasionally low platelet concentrations can lead to clotting problems.
- Dermatological: skin may become dry or discoloured. Excess hair growth on the face, arms and down the back is often seen..
- Renal, liver and pancreatic function: in advanced stages these three systems can all be impaired.
- Neuro-psychiatric: cognition is slowed, concentration is impaired and thinking becomes very restricted with states of depression and anxiety.
- Muscle changes: in advanced stages of starvation there can be severe muscle weakness.
Heart and Circulation:
- With weight loss the heart rate slows below its normal rate of 60 to 70 beats per minute. There are sometimes dangerous changes in the electrical activity of the heart as seen on a cardiogram.
- Heart affects are more dangerous if there are also abnormalities in the body chemistry, particularly low potassium. The most serious consequence is cardiac arrest.
- The blood pressure is low and this can be associated with fainting, especially with changes in posture.
- Bones become thin due to lack of nutrients particularly calcium and vitamin D. Low oestrogen levels also play a part.
- If starvation starts in adolescence before full stature is reached there can be growth retardation.
- The milder form of bone thinning is called osteopaenia and the more severe state is osteoporosis. These conditions can lead to fractures after quite minor injuries.
Kidneys, Liver and Pancreas:
- In advanced starvation there can be abnormalities in the function of all these organs.
- Because of poor insulation when patients are underweight there is cold intolerance.
- There is also poor circulation to the feet and hands which can cause a painful condition called Raynaud’s phenomenon.
- Very low body temperature or hypothermia is potentially fatal. It can cause further slowing of heart rate and abnormal contractions.
- There can be reduced manufacture of haemoglobin, the oxygen carrying chemical in the red blood cells. This is anaemia which causes weakness and tiredness.
- Production of white blood cells is also impaired in anorexia nervosa and this will weaken the body’s defenses to infections.
- The blood platelet concentrations may be low. Platelets are important in the formation of clots and in rare cases there is the possibility of a bleeding tendency when the platelets are low.
- Skin may be dry or blotchy or have an unhealthy grey or yellow coloration. Sometimes, excess hair grows on the face, arms and down the back. This is a fine downy hair called lanugo.
- In starvation states the ovaries and pituitary produce very low amounts of female sex hormones leading to loss of periods and infertility if not reversed. The equivalent hormone changes also occur in male patients.
- There are also reduced levels of thyroid hormones. Blood cortisol, the stress hormone, can be high and this may contribute to thinning of the bones.