Human Starvation and Survival Biology Quiz

High protein diet

Amino acids from protein breakdown

Sarcopenia

Starvation

Physiological and pathological

To do no harm and treat malnutrition

It often involves deficiencies in multiple macronutrients

Similar to protein deficiency

They felt terrible psychologically and physically

They often struggle to regain normal health

Protein-energy malnutrition

23%

Gcn2 and AMPK

Fatigue, immunodeficiency, and reduced tolerance to stress

Increased risk of chronic diseases and small gestational age

The first 1000 days from conception to the second birthday

Fluid accumulation and failed adaptation

Diarrhea, pneumonia, and tuberculosis

Cautious intervention, treating infections, and long-term prevention programs to increase food security

Micronutrient deficiencies and stressors like trauma, cancer, or inflammation

Hypermetabolic and hypometabolic responses

1. Cachexia – cancer, systemic inflammation cortisol, epinephrine
2. Hormone excess or deficiency like decrease in insulin, insulin growth factor
3. Old age – sarcopenia
4. Protein-energy malnutrition – starvation
5. Inactivity – disuse atrophy bed rest, space flight, 0 gravity
6. Neuromuscular disease.

The importance of intervening before muscle atrophy becomes too intense is to prevent the loss of lean mass and potentially compromising functions.

A major increase in urinary nitrogen signifies a negative nitrogen balance, indicating the loss of lean mass and potential compromise of bodily functions due to protein breakdown.

The potential consequences of not addressing the metabolic response to injury and illness promptly include the development of sarcopenia and the risk of muscle atrophy due to various factors such as cachexia, hormonal imbalances, old age, malnutrition, inactivity, and neuromuscular diseases.

Physiological starvation is adaptive to promote survival, while pathological starvation involves some sort of stress that compromises adaptation, such as infection, cancer, drugs, or surgery.

The challenges include the inability to put healthy humans on a diet to induce malnutrition, as it goes against the principle of 'do no harm.' Ethical considerations dictate that individuals with malnutrition must be treated rather than observed, and standard care should be offered as a control group in research studies.

Malnutrition is a complex energy deficiency along with protein, and it rarely involves a single nutrient deficiency. It often includes deficiencies in other macronutrients, making it a multifaceted condition.

Zinc deficiency can cause side effects and symptoms similar to protein deficiency, making it challenging to diagnose subclinical infections. Additionally, plasma zinc levels may not accurately reflect zinc status.

Individuals fed a low-protein and low-energy diet for six months experienced severe psychological and physical distress, making it difficult for them to recover from the diet.

The Dutch Famine resulted in epigenetic changes, with infants facing chronic disease risks and small gestational age.

Edematous undernutrition leads to fluid accumulation and is associated with failed adaptation and subclinical infections.

Cellular regulation in starvation involves Gcn2 and AMPK, contributing to successful adaptation at the cellular level.

Infections such as diarrhea, pneumonia, and tuberculosis are common in undernourished individuals, impacting immunity and overall health.

Protein-energy malnutrition (PEM) leads to clinical features such as fatigue, immunodeficiency, and reduced tolerance to stress.

Chronic insufficient food intake leads to starvation, resulting in the body's energy expenditure and protein requirement reducing to survive long-term undernutrition.

Medical nutrition therapy for rehabilitation involves cautious intervention, treating infections, and long-term prevention programs to increase food security.