Starvation


Starvation is a severe deficiency in caloric energy intake, below the level needed to maintain an organism's life. It is the most extreme form of malnutrition. In humans, prolonged starvation can cause permanent organ damage and eventually, death. The term inanition refers to the symptoms and effects of starvation. Starvation may have a natural cause or be man-made. Deliberately inflicting starvation upon a population is a crime according to international criminal law and may also be used as a means of torture or execution.
According to the World Health Organization, hunger is the single gravest threat to the world's public health. The WHO also states that malnutrition is by far the biggest contributor to child mortality, present in half of all cases. Undernutrition is a contributory factor in the death of 3.1 million children under five every year. The results also demonstrates that as global hunger levels have stabilized, however, despite some progress in specific areas such as stunting and exclusive breastfeeding, an alarming number of people still face food insecurity and malnutrition. In fact, the world has been set back 15 years, with levels of undernourishment similar to those in 2008-2009, with between 713 and 757 million people undernourished in 2023, and over 152 million more than in 2019 when the mid-range was 733 million.
The bloated stomach represents a form of malnutrition called kwashiorkor. The exact pathogenesis of kwashiorkor is not clear, as initially it was thought to relate to diets high in carbohydrates but low in protein. While many patients have low albumin, this is thought to be a consequence of the condition. Possible causes such as aflatoxin poisoning, oxidative stress, immune dysregulation, and altered gut microbiota have been suggested. Treatment can help mitigate symptoms such as the pictured weight loss and muscle wasting, however prevention is of utmost importance.
Without any food, humans usually die in around 2 months. There was a case when someone survived over a year under medical supervision. Lean people can usually survive with a loss of up to 18% of their body mass; obese people can tolerate more, possibly over 20%. Females may survive longer than males due to their higher body fat content at the same BMI.

Signs and symptoms

The following are some of the symptoms of starvation:

Changes in behaviour or mental status

The beginning stages of starvation impact mental status and behaviours. These symptoms show up as irritable and/or unstable mood, fatigue, trouble concentrating, and preoccupation with food thoughts. People with those symptoms tend to be easily distracted and have no energy. Psychological effects are profound, including depression, anxiety, and a decrease in cognitive functions.

Physical signs

As starvation progresses, the physical symptoms set in. The timing of these symptoms depends on age, size, and overall health. It usually takes days to weeks, and includes weakness, fast heart rate, shallow breaths that are slowed, thirst, and constipation. There may also be diarrhea in some cases. The eyes begin to sink in and glass over. The muscles begin to become smaller and muscle wasting sets in. Tiredness and dizziness also commonly occur, especially from any physical task. The skin is often overly pale. One prominent sign in children is a swollen belly. Skin loosens and turns pale in color, and there may be swelling of the feet and ankles.

Weakened immune system

Symptoms of starvation may also appear as a weakened immune system, slow wound healing, and poor response to infection. Rashes may develop on the skin. The body directs any nutrients available to keeping organs functioning.

Other symptoms

Other effects of starvation may include:
Starvation Induced Hepatitis and/or reduced liver function
The symptoms of starvation show up in three stages. Phase one and two can show up in anyone that skips meals, diets, and goes through fasting. Phase three is more severe, can be fatal, and results from long-term starvation.
Phase one: When meals are skipped, the body begins to maintain blood sugar levels by degrading glycogen in the liver and breaking down stored fat and protein. The liver can provide glucose for the first few hours. After that, the body begins to break down fat and protein. The body uses fatty acids as an energy source for muscles but lowers the amount of glucose sent to the brain. Another chemical that comes from fatty acids is glycerol. It can be used as glucose for energy but eventually runs out.
Phase two: Phase two can last for weeks at a time. In this phase, the body mainly uses stored fat for energy. The breakdown occurs in the liver and turns fat into ketones. After fasting for one week, the brain will use these ketones and any available glucose. Using ketones lowers the need for glucose, and the body slows the breakdown of proteins.
Phase three: By this point, the fat stores are gone, and the body begins to turn to stored protein for energy. This means it needs to break down muscle tissues full of protein; the muscles break down very quickly. Protein is essential for cells to work correctly, and when it runs out, the cells can no longer function.
The cause of death due to starvation is usually an infection or the result of tissue breakdown. This is due to the body becoming unable to produce enough energy to fight off bacteria and viruses. The final stage of starvation includes signals like hair color loss, skin flaking, swelling in the extremities, and a bloated belly. Even though they may feel hunger, people in the final stage of starvation usually cannot eat enough food to recover without significant medical intervention.

Causes

Starvation occurs when the body expends more energy than it takes in for an extended period of time. This imbalance can arise from one or more medical conditions or circumstantial situations, which can include:
Medical reasons
Circumstantial causes
  • Child, elder, or dependent abuse
  • Famine for any reason, such as political strife and war
  • Hunger striking
  • Excessive fasting
  • Poverty
  • Torture

    Biochemistry

With a typical high-carbohydrate diet, the human body relies on free blood glucose as its primary energy source. Glucose can be obtained directly from dietary sugars and by the breakdown of other carbohydrates. In the absence of dietary sugars and carbohydrates, glucose is obtained from the breakdown of stored glycogen. Glycogen is a readily-accessible storage form of glucose, stored in notable quantities in the liver and skeletal muscle.
After the exhaustion of the glycogen reserve, and for the next two to three days, fatty acids become the principal metabolic fuel. At first, the brain continues to use glucose. If a non-brain tissue is using fatty acids as its metabolic fuel, the use of glucose in the same tissue is switched off. Thus, when fatty acids are being broken down for energy, all of the remaining glucose is made available for use by the brain.
After two or three days of fasting, the liver begins to synthesize ketone bodies from precursors obtained from fatty acid breakdown. The brain uses these ketone bodies as fuel, thus cutting its requirement for glucose. After fasting for three days, the brain gets 30% of its energy from ketone bodies. After four days, this may increase to 70% or more. Thus, the production of ketone bodies cuts the brain's glucose requirement from 80 g per day to 30 g per day, about 35% of normal, with 65% derived from ketone bodies. But of the brain's remaining 30 g requirement, 20 g per day can be produced by the liver from glycerol. This still leaves a deficit of about 10 g of glucose per day that must be supplied from another source; this other source will be the body's own proteins.
After exhaustion of fat stores, the cells in the body begin to break down protein. This releases alanine and lactate produced from pyruvate, which can be converted into glucose by the liver. Since much of human muscle mass is protein, this phenomenon is responsible for the wasting away of muscle mass seen in starvation. However, the body is able to choose which cells will break down protein and which will not. About 2–3 g of protein has to be broken down to synthesize 1 g of glucose; about 20–30 g of protein is broken down each day to make 10 g of glucose to keep the brain alive. However, this number may decrease the longer the fasting period is continued, in order to conserve protein.
Starvation ensues when the fat reserves are completely exhausted and protein is the only fuel source available to the body. Thus, after periods of starvation, the loss of body protein affects the function of important organs, and death results, even if there are still fat reserves left. In a leaner person, the fat reserves are depleted faster, and the protein, sooner, therefore death occurs sooner. Ultimately, the cause of death is in general cardiac arrhythmia or cardiac arrest, brought on by tissue degradation and electrolyte imbalances. Conditions like metabolic acidosis may also kill starving people.

Prevention

Starvation can be caused by factors beyond the control of the individual. The Rome Declaration on World Food Security outlines several policies aimed at increasing food security and, consequently, preventing starvation. These include:
Supporting farmers in areas of food insecurity through such measures as free or subsidized fertilizers and seeds increases food harvest and reduces food prices.
Starvation is commonly used as a method of warfare, however, it has been outlawed and is now a crime. Notable incidents in history include the blockade of Germany, blockade of Biafra, and the ongoing blockade of Gaza.