The Body's Process During Starvation
When deprived of calories, the human body enters a survival mode, systematically breaking down its own tissues for energy. This process unfolds in several stages:
Stage 1: Glycogen and Fat Stores
Initially, the body uses readily available glucose from stored glycogen in the liver and muscles. Once these stores are depleted (typically within a day), it transitions to breaking down stored fat for fuel through a process called ketosis. This can sustain the body for several weeks, depending on fat reserves.
Stage 2: Muscle Protein Breakdown
When fat reserves are exhausted, the body resorts to breaking down muscle protein. This is a critical and highly damaging phase where muscle wasting accelerates rapidly, including the cardiac muscle. Protein is essential for virtually all cellular functions, and its depletion severely compromises organ function.
The Cardiovascular Consequences
Starvation places immense stress on the heart and circulatory system, with potential complications including:
- Bradycardia and Hypotension: A dangerously slow heart rate (bradycardia) and low blood pressure (hypotension) are common as the body conserves energy.
- Myocardial Atrophy: The heart muscle itself shrinks and weakens, reducing its ability to pump blood effectively.
- Arrhythmia and Heart Failure: Electrolyte imbalances, particularly low potassium (hypokalemia), can trigger irregular heartbeats (arrhythmia), which can be fatal. Long-term cardiac strain can lead to heart failure.
- Pericardial Effusion: Fluid may build up in the sac surrounding the heart, further impairing its function.
Kidney Damage and Dysfunction
Kidney function is severely compromised during starvation, with potential for both short- and long-term damage:
- Acute Kidney Injury (AKI): Severe dehydration and electrolyte disturbances can cause a sudden decline in kidney function, which can be life-threatening if not addressed promptly.
- Chronic Kidney Disease (CKD): Long-term malnutrition can lead to permanent damage, increasing the risk of CKD. Factors like chronic inflammation, dehydration, and electrolyte abnormalities all contribute.
- Kidney Stones: The risk of developing kidney stones, particularly from calcium oxalate or ammonium urate, increases due to metabolic changes.
Psychological and Cognitive Effects
The brain, heavily dependent on nutrients, suffers significantly during starvation:
- Mood Changes: Many individuals experience severe depression, anxiety, irritability, and profound mood swings. In some cases, post-traumatic stress disorder (PTSD) can develop.
- Cognitive Decline: Concentration, alertness, and judgment are often impaired. Apathy and social withdrawal are also common.
- Obsession with Food: A constant preoccupation with food and eating often develops, with changes in eating habits and rituals that persist even during recovery.
Other Systemic Illnesses
Starvation's reach extends to nearly every bodily system:
- Weakened Immune System: The body's ability to fight infection is severely diminished, making individuals highly vulnerable to common illnesses like pneumonia.
- Anemia: A lack of key nutrients like iron, vitamin B12, and folic acid can lead to anemia, causing fatigue, paleness, and poor circulation.
- Osteoporosis: The breakdown of bone tissue results in low bone density and an increased risk of fractures.
- Gastrointestinal Distress: This can include constipation, diarrhea, and gastroparesis (delayed stomach emptying).
- Reproductive Issues: Hormone suppression can lead to amenorrhea (absence of menstrual periods) and infertility.
Understanding the Risks of Starvation vs. Normal State
| Feature | Starvation State | Normal State |
|---|---|---|
| Primary Fuel Source | Ketones from fat, then muscle protein | Glucose from carbohydrates |
| Metabolic Rate | Significantly decreased to conserve energy | Stable basal metabolic rate |
| Heart Rate | Abnormally slow (bradycardia) | Normal resting rate (60-100 bpm) |
| Immune Function | Severely compromised | Strong and functional |
| Body Mass | Significant loss of fat and muscle | Stable weight and muscle mass |
| Electrolyte Balance | Depleted and imbalanced | Maintained at healthy levels |
Conclusion
What sickness can starvation cause is a matter of profound and widespread medical concern, affecting nearly every system in the body. While many conditions are potentially reversible with careful medical and nutritional intervention, the path to recovery is fraught with risks, including the potentially fatal refeeding syndrome. The psychological scars and long-term developmental issues, especially for children, can be lasting. Addressing starvation requires comprehensive care to navigate these complex health challenges and support a return to health. Feeding America offers resources and information on the devastating effects of hunger.
