BackProtein-Related Disorders: Effects of Protein Deficiency and Excess
Study Guide - Smart Notes
Tailored notes based on your materials, expanded with key definitions, examples, and context.
Protein-Related Disorders
What Happens if We Consume Too Little or Too Much Protein?
Protein is an essential macronutrient required for growth, maintenance, and repair of body tissues. Both insufficient and excessive protein intake can have significant health consequences, especially in extreme cases.
Too little protein can cause malnutrition and health disorders.
Too much protein may have unclear health effects; research shows conflicting risks and benefits.
Lack of Protein: Major Disorders
Protein deficiency can lead to several health issues, particularly in children and populations with limited food access.
Health Issue | Description |
|---|---|
Marasmus ("Skin & bones") | Protein-Energy Malnutrition (PEM) - chronic calorie deficiency with protein deficiency. Characterized by severe wasting, loss of fat and muscle, and "skin & bones" appearance. |
Kwashiorkor ("Bloated belly") | Acute protein deficiency with adequate energy intake. Causes edema (swelling), enlarged liver, and "bloated belly" appearance. |
Marasmic kwashiorkor | Combination of chronic and acute deficiencies. Can lead to fatal outcomes. |
Additional info: Marasmus typically affects infants and young children, while kwashiorkor is more common in older children after weaning.
Other Nutrient Deficiencies Associated with Protein Deficiency
Kidney disease and scurvy can result from overall malnutrition.
Zinc deficiency is also common in protein-deficient diets.
Kwashiorkor: Pathophysiology and Symptoms
Kwashiorkor is a disease caused by a severe protein deficiency, often occurring when a child is weaned from breast milk and fed a diet high in carbohydrates but low in protein.
Edema (swelling): The body cannot produce enough proteins (such as albumin) to maintain fluid balance, leading to fluid accumulation in tissues.
Fatty liver: The liver cannot process fat properly due to lack of protein, causing fat buildup.
Muscle wasting: The body breaks down muscle tissue for protein, resulting in weakness.
Impaired immune function: Protein deficiency weakens the immune system, increasing susceptibility to infections.
Example: A child with kwashiorkor may present with a swollen belly, thin limbs, and frequent infections.
Mechanism of Edema in Kwashiorkor
Proteins in the blood (especially albumin) help maintain osmotic pressure, keeping fluid in blood vessels.
When protein is deficient, fluid leaks out of the blood into tissues, causing swelling (edema).
Equation:
Prevention and Treatment
Ensure adequate intake of high-quality protein from diverse sources (meat, dairy, legumes, grains).
Address underlying causes such as poverty, food insecurity, and lack of nutrition education.
Medical intervention may be required for severe cases, including gradual refeeding and treatment of infections.
Additional info: Eating too much protein is unlikely unless consuming 10x the RDA, which is rare in most populations.
