What is the incidence rate of protein energy malnutrition?

October 29, 2025 •

5 min read

According to the Global Burden of Disease Study 2019, the global age-standardised prevalence rate of protein-energy malnutrition (PEM) showed an upward trend, highlighting its persistent challenge worldwide. This condition affects millions, with particularly severe impacts in vulnerable populations and low-income countries.

Quick Summary

This article explores the incidence rate of protein energy malnutrition, detailing its variable global trends, contributing factors, and significant consequences. The focus is on the disproportionate impact on vulnerable groups and the critical need for effective interventions. The piece synthesizes key findings from international health reports to provide a comprehensive overview.

Key Points

Prevalence vs. Incidence: Health reports often focus on the prevalence (total cases) of PEM rather than incidence (new cases) due to its chronic nature.
Global Burden: In 2019, over 147 million PEM cases were reported globally, and the age-standardised prevalence rate saw an upward trend between 1990 and 2019.
Vulnerable Populations: Children under five and the elderly are disproportionately affected by PEM, facing higher morbidity and mortality risks.
Socioeconomic Factors: Poverty, poor sanitation, and lack of healthcare access are major drivers, particularly in low-income countries.
Severe Consequences: Untreated PEM can lead to permanent physical and cognitive impairments, compromised immune function, organ damage, and increased mortality.
Prevention and Treatment: Strategies include promoting proper breastfeeding and weaning, nutritional education, micronutrient supplementation, and controlled refeeding for severe cases.

Defining the Incidence of Protein-Energy Malnutrition

Protein-energy malnutrition (PEM), often referred to as protein-calorie malnutrition (PCM), is a severe deficiency of protein and calories, which can impair normal physiological processes and lead to significant health problems. While the term 'incidence rate' (the number of new cases per population at risk) is used, health reports often focus on 'prevalence,' the total number of cases existing at a given time. Prevalence data provides a more complete picture of the ongoing, widespread nature of PEM, which is both acute and chronic. Understanding both the new occurrences and the total burden is critical for global health strategy.

Global and Regional Prevalence Trends

Global health data reveals complex and varied patterns in the burden of protein-energy malnutrition. A comprehensive analysis based on the Global Burden of Disease Study 2019 provides key insights:

Global Prevalence: In 2019, there were over 147 million reported cases of PEM globally. The age-standardised prevalence rate showed a slight but concerning upward trend from 1990 to 2019. Forecasts suggest this trend may continue, with cases potentially exceeding 160 million by 2044.
Regional Disparities: The burden of PEM is not evenly distributed. Regions with low socioeconomic indices (SDI) carry the highest burden of severe cases and deaths. For example, in 2019, South Asia had one of the highest age-standardized prevalence rates, at 3316.7 per 100,000 population. In contrast, regions like Australasia had much lower rates.
Impact on Children: In 2022, the World Health Organization (WHO) estimated that 149 million children under five were stunted and 45 million were wasted globally. PEM accounts for nearly half of all deaths in children under five in developing countries. Low-income countries showed a 13.7% increase in stunted children between 2012 and 2024, highlighting a serious and worsening problem.

Classifications and Characteristics of PEM

PEM manifests in several forms, which often depend on the specific dietary deficiency and the patient's age and health status. The two most classic and severe forms are marasmus and kwashiorkor, though mixed forms are common.

Common Forms of Protein-Energy Malnutrition

Marasmus: This is the most common form in young children, resulting from a severe deficiency of both protein and total calories. It leads to significant weight loss, muscle wasting, and a wasted, 'monkey-like' facial appearance.
Kwashiorkor: Caused primarily by a protein deficiency despite relatively adequate calorie intake. A key characteristic is the presence of edema (swelling), particularly in the feet, ankles, and face, leading to a 'moon face'.
Marasmic-Kwashiorkor: A severe combined form showing symptoms of both marasmus (wasting) and kwashiorkor (edema).

Comparison of Marasmus and Kwashiorkor


Characteristic	Marasmus	Kwashiorkor
Primary Cause	Severe protein and calorie deficiency	Severe protein deficiency, adequate calories
Visible Signs	Severe wasting, wrinkled skin, extreme emaciation	Edema (swelling) of limbs and face
Body Fat/Muscle	Minimal to no body fat or muscle remaining	Variable muscle wasting, but fat reserves may be present
Appearance	Appears emaciated or 'monkey-like'	Characterized by a 'moon face' due to swelling
Age of Onset	Typically appears between 6 months and 1 year	Often appears around 1 year of age, post-weaning
Other Symptoms	Frequent infections, diarrhea, stunted growth	Diarrhea, fatty liver, hair and skin changes

Contributing Risk Factors

The incidence of PEM is influenced by a complex interplay of socioeconomic, environmental, and biological factors. Addressing the high incidence requires tackling these root causes simultaneously.

Poverty and Socioeconomic Status: Low-income households and underdeveloped regions face the highest risk, with insufficient resources for adequate nutrition. Studies consistently show a strong link between poverty and PEM.
Infections and Disease: The vicious cycle of malnutrition and infection is well-documented. Malnutrition weakens the immune system, increasing susceptibility to infections like measles, pneumonia, and gastrointestinal issues, which in turn worsen nutritional status through loss of appetite and nutrient depletion.
Poor Feeding Practices: Lack of proper breastfeeding and ineffective weaning are significant contributors, especially in children under five. Providing contaminated food or water during weaning can also lead to infections that exacerbate malnutrition.
Maternal Health and Literacy: The nutritional status of the mother directly affects the child. Poor maternal nutrition can lead to low birth weight, and low maternal literacy is linked to poorer feeding practices and higher PEM rates.
Access to Healthcare: Inadequate access to healthcare, including vaccinations and nutritional support, is a major barrier to preventing and treating PEM effectively.
Age-Related Factors: Both children and the elderly are highly vulnerable. Older adults, particularly in long-term care or with chronic illness, face high prevalence rates (30-50%). Children's higher energy and protein needs per kilogram make them especially susceptible during growth spurts.

Long-Term Consequences of PEM

The effects of protein-energy malnutrition can be devastating and long-lasting, impacting physical, cognitive, and immune system development.

Permanent Physical Retardation: Stunting (low height for age) and other forms of growth failure, particularly when occurring early in life, can be irreversible.
Cognitive and Neurological Impairment: Malnutrition during critical brain development stages can have lasting negative effects on intellectual and psychological development.
Immunodeficiency: A compromised immune system leaves individuals, especially children, vulnerable to recurrent, severe infections. Sepsis and overwhelming bacteremia are common causes of death in malnourished individuals.
Organ Dysfunction: Severe PEM can lead to various organ failures, including heart failure, fatty liver disease, and kidney insufficiency.

Addressing the Incidence of PEM

Addressing the incidence of protein-energy malnutrition requires a multi-faceted approach focusing on prevention, treatment, and long-term care.

Key strategies include:

Promoting Breastfeeding and Proper Weaning: Exclusive breastfeeding for the first six months, followed by safe and nutritionally adequate complementary feeding, is crucial for infant health.
Nutritional Education: Educating caregivers on proper feeding practices and balanced diets using locally available resources can have a significant impact.
Micronutrient Supplementation: Providing supplements for essential vitamins and minerals like Vitamin A, zinc, and iron helps address common deficiencies and bolster the immune system.
Integrated Healthcare Services: Linking nutritional programs with health services like immunization, infection control, and growth monitoring is vital for comprehensive care.
Targeted Therapeutic Feeding: For severe cases, specialized therapeutic foods and careful refeeding protocols, often involving inpatient care, are necessary to prevent refeeding syndrome, a potentially fatal complication.

Conclusion

The incidence and prevalence of protein-energy malnutrition remain a critical global health challenge, especially in low-income regions and among vulnerable populations like children and the elderly. While overall global trends have been complex, persistent and sometimes rising prevalence rates underscore the need for sustained and targeted interventions. Effective strategies must address the intertwined issues of poverty, infection, and inadequate dietary practices. By implementing comprehensive nutritional programs, improving healthcare access, and focusing on education, the devastating impact of PEM can be mitigated, leading to improved health outcomes and reduced mortality worldwide. Efforts must be continuous, as highlighted by resources from organizations such as the World Health Organization and Medscape.

Frequently Asked Questions

The term 'incidence' refers to new cases, but due to PEM's chronic nature, health organizations like WHO more commonly report 'prevalence,' or the total number of cases. PEM is often measured using indicators like stunting (low height-for-age), wasting (low weight-for-height), and underweight (low weight-for-age).

Marasmus is caused by a severe deficiency of both protein and calories, leading to extreme wasting and emaciation. Kwashiorkor is primarily caused by a severe protein deficiency despite adequate calorie intake, resulting in edema (swelling).

Globally, children under five and the elderly are most vulnerable. Children face higher risk due to rapid growth needs, while the elderly often develop PEM due to chronic illness, decreased appetite, or insufficient care.

Yes, PEM can be prevented by addressing its root causes, such as poverty, lack of access to nutritious food, and poor sanitation. Key preventive measures include promoting proper breastfeeding and weaning practices, nutritional education, and providing essential micronutrient supplementation.

Long-term effects include permanent physical growth retardation, irreversible cognitive impairment, and a weakened immune system that increases susceptibility to infections. Organ damage, such as fatty liver disease and heart failure, can also occur.

Severe PEM requires careful, phased treatment, typically starting in a hospital setting. The World Health Organization (WHO) recommends three phases: stabilization (addressing immediate threats like infection and electrolyte imbalance), rehabilitation (gradual nutritional repletion), and follow-up care.

Refeeding syndrome is a dangerous metabolic complication that can occur during the aggressive refeeding of a malnourished patient. Rapid changes in fluid and electrolyte levels can lead to severe issues like fluid overload, heart arrhythmias, and electrolyte deficiencies, which can be fatal.