Nutrition Diet: Which disease is caused by lack of proteins?

October 4, 2025 •

3 min read

According to UNICEF, undernutrition is linked to nearly half of all deaths in children under the age of five worldwide. The most severe disease caused by lack of proteins is kwashiorkor, a life-threatening form of malnutrition characterized by a defining symptom of fluid retention, or edema.

Quick Summary

This article explains how kwashiorkor is the primary severe disease caused by a lack of proteins. It details the symptoms, such as edema and muscle wasting, and contrasts it with marasmus. The content also addresses other effects of protein deficiency, covers treatment and prevention methods, and highlights the crucial role of adequate protein intake.

Key Points

Kwashiorkor is the primary disease: This condition, caused by severe protein deficiency, is marked by edema, a swollen abdomen, and skin and hair changes.
Marasmus is different: Distinct from kwashiorkor, marasmus is a result of overall calorie and protein starvation, leading to severe emaciation without the trademark swelling.
Immune function is compromised: Protein deficiency can weaken the immune system, making individuals more vulnerable to infections due to impaired antibody production.
Cognitive effects are significant: Inadequate protein intake can lead to cognitive decline, learning impairment, and behavioral changes, impacting brain function over time.
Prevention is a balanced diet: Consuming a variety of high-quality protein sources, from both animal and plant origins, is the best way to prevent protein deficiency and support overall health.
Refeeding is a delicate process: For severe cases, reintroducing nutrients must be done cautiously under medical supervision to avoid the potentially fatal complications of refeeding syndrome.

The Vital Role of Protein

Protein, composed of amino acids, is essential for numerous bodily functions including tissue building, enzyme production, and hormone synthesis. The body requires a constant supply through diet as it cannot store protein. Severe protein deficiency can lead to serious health issues, most notably kwashiorkor.

Kwashiorkor: The Disease of Severe Protein Deficiency

Kwashiorkor, meaning "the sickness the baby gets when the new baby comes" in a Ghanaian language, typically affects young children transitioning from protein-rich breast milk to carbohydrate-heavy diets. Its hallmark is edema, causing swelling in the limbs and face, and a distended abdomen. This swelling can hide muscle wasting.

Symptoms and Complications of Kwashiorkor

Kwashiorkor presents with severe symptoms:

Edema: Swelling in extremities and face due to low albumin.
Growth Failure: Stunted growth and poor weight gain.
Dermatitis: Dry, peeling skin.
Hair Changes: Dry, brittle, and discolored hair.
Fatigue and Apathy: Lethargy and irritability.
Compromised Immunity: Increased risk of fatal infections.
Enlarged Liver: Fatty liver is common.

Kwashiorkor vs. Marasmus: A Critical Distinction

Kwashiorkor and marasmus are both severe forms of protein-energy malnutrition, but they differ. Kwashiorkor primarily results from severe protein deficiency, often with adequate calorie intake, and is characterized by edema. Marasmus is a deficiency of both protein and calories, leading to extreme emaciation. For more details on the differences, refer to {Link: Health.com https://www.health.com/how-to-eat-100-grams-of-protein-a-day-11695883}.

The Broader Impact of Protein Deficiency

Beyond kwashiorkor, chronic or mild protein deficiency can negatively impact health.

Effects on Body Systems

Immune System: Protein is crucial for immune function, and deficiency weakens the system, increasing infection susceptibility.
Cognitive Function: Protein intake is linked to brain health. Deficiency can affect neurotransmitter synthesis, leading to cognitive decline.
Muscle and Tissue Health: Lack of protein causes muscle breakdown, leading to weakness and wasting.
Hair, Skin, and Nails: Protein deficiency can cause thinning hair, brittle nails, and dry skin.

Treatment and Prevention of Protein Deficiency

Treating severe protein deficiency requires medical supervision and a gradual reintroduction of nutrients to avoid refeeding syndrome. Prevention focuses on ensuring adequate protein intake through a varied diet.

High-Quality Protein Sources

Animal-Based Proteins: Lean meats, eggs, and dairy.
Plant-Based Proteins: Legumes, nuts, seeds, soy products, and quinoa.

A mixed diet provides essential amino acids. Vegetarians and vegans should combine different plant proteins for a complete amino acid profile.

Conclusion

Kwashiorkor is the most severe disease caused by lack of proteins, characterized by edema, while milder deficiencies also have health consequences. Protein deficiency impairs immunity, cognitive function, and tissue health. Consuming a varied diet with high-quality protein sources is vital for prevention and overall health.

Addressing Nutritional Deficiencies

Recognize the signs: Early signs of moderate protein deficiency include fatigue, hair thinning, and slow healing, often preceding more severe symptoms like edema.

Distinguish Kwashiorkor and Marasmus: Kwashiorkor's hallmark is edema (swelling) due to primary protein deficiency, while marasmus is characterized by severe wasting from a broader lack of calories and protein.

Understand the Risks: Individuals transitioning from high-protein diets (like breastfeeding) to low-protein alternatives are at high risk, particularly in developing regions.

Prioritize Complete Proteins: Incorporate a variety of high-quality protein sources—animal-based (meat, eggs, dairy) or carefully combined plant-based foods—to ensure all essential amino acids are consumed.

Consult a professional: Severe malnutrition requires cautious, supervised re-feeding to prevent refeeding syndrome, a dangerous metabolic complication.

Frequently Asked Questions

Kwashiorkor is a severe form of protein malnutrition. The swollen belly and edema (fluid retention) are caused by low levels of albumin, a protein that maintains fluid balance in the blood. Without enough albumin, fluid leaks into the body's tissues.

Kwashiorkor is primarily a protein deficiency with relatively sufficient calories, causing edema. Marasmus is a deficiency of both protein and calories, resulting in extreme emaciation and muscle wasting without the characteristic swelling.

Early signs can include fatigue, irritability, thinning hair, dry skin, and slow wound healing. As it progresses, symptoms like loss of muscle mass, edema, and impaired immune function can develop.

A well-planned vegetarian or vegan diet can provide all necessary protein. However, if not carefully planned with a variety of plant-based protein sources, it could lead to deficiencies, as some plant proteins may lack certain essential amino acids.

Refeeding syndrome is a potentially fatal metabolic complication that occurs when severely malnourished individuals are fed too aggressively. It involves dangerous shifts in fluid and electrolytes, highlighting the need for cautious nutritional rehabilitation in treating kwashiorkor.

Treatment involves a gradual and careful introduction of a nutrient-dense diet, starting with carbohydrates and fats before introducing proteins. This process is medically supervised to correct vitamin and mineral deficiencies and prevent refeeding syndrome.

Yes, protein deficiency can impair cognitive function, impacting memory, learning, and mood. This is because proteins and their amino acid components are crucial for synthesizing neurotransmitters in the brain.