What are the main causes of malnutrition?

December 5, 2025 •

3 min read

According to the World Health Organization, nearly half of all deaths among children under five are linked to undernutrition. The main causes of malnutrition are complex and interconnected, ranging from individual health issues to broad socioeconomic and environmental factors that affect populations globally.

Quick Summary

Malnutrition stems from an imbalance of nutrients, including both underconsumption and overconsumption. Key drivers include food insecurity, diseases that impair nutrient absorption, poor sanitation, and underlying socioeconomic issues like poverty and inadequate education. A vicious cycle of disease and poor nutrition is common.

Key Points

Inadequate Diet & Disease: The most immediate causes are a lack of quality food or health conditions that interfere with nutrient absorption, creating a dangerous feedback loop.
Poverty is a Root Cause: Socioeconomic factors like poverty and low income are major drivers, limiting access to nutritious food, clean water, and adequate healthcare.
Malnutrition Has Two Faces: The condition includes both undernutrition (deficiencies) and overnutrition (excesses leading to obesity), both of which have serious health consequences.
Environmental Factors Matter: Poor sanitation, unsafe water, and environmental shocks like climate change contribute to disease and food insecurity, worsening malnutrition.
Vulnerable Groups at Risk: Children, the elderly, pregnant women, and the chronically ill are among the populations most susceptible to malnutrition and its devastating effects.
Education is Key: Lack of nutritional knowledge can lead to poor dietary choices, even in areas with food availability, contributing to both under- and overnutrition.
Political and Social Context: War, political instability, and gender inequality at the societal level can disrupt food distribution and resource control, fueling malnutrition.

Malnutrition is a critical global health issue, encompassing deficiencies, excesses, or imbalances in a person's intake of energy and/or nutrients. It is not a single problem but a complex condition driven by a multitude of factors across various levels. The causes can be categorized into immediate (direct food and health issues), underlying (household and environmental factors), and basic (societal and political). Understanding this layered framework is essential for effective prevention and treatment strategies.

Immediate Causes: Diet and Disease

At the most direct level, malnutrition is a result of either inadequate dietary intake or diseases that interfere with nutrient absorption or increase the body's nutrient needs. These two factors are often locked in a cycle, where one exacerbates the other.

Inadequate Dietary Intake

A lack of sufficient food or a diet lacking essential nutrients are primary dietary causes. This can include insufficient food quantity, poor dietary quality leading to micronutrient deficiencies or overnutrition, and inadequate feeding practices for infants and children.

Disease and Health Conditions

Various health issues contribute to malnutrition. Infections like diarrhea, measles, respiratory infections, and malaria can cause undernutrition by reducing appetite and increasing nutrient loss. Chronic illnesses, mental health conditions, and increased metabolic needs from injuries also play a significant role.

Underlying Causes: Societal and Environmental Factors

Household and community-level factors create environments where malnutrition is more likely.

Food Insecurity: This is a major underlying cause, involving unreliable access to adequate, nutritious food due to economic instability, conflict, or agricultural challenges.
Inadequate Care and Feeding Practices: Lack of education or traditional beliefs can lead to poor feeding practices, particularly for children.
Poor Sanitation and Hygiene: Limited access to clean water and sanitation increases the risk of infections that worsen nutritional status.
Inadequate Healthcare Access: Restricted access to healthcare hinders the prevention and treatment of diseases contributing to malnutrition.

Basic Causes: Political and Economic Factors

These root causes shape the underlying factors and influence a society's overall health.

Poverty: A significant basic cause, poverty limits access to essential resources like nutritious food, clean water, sanitation, and healthcare, perpetuating a cycle of malnutrition and hindering economic development.
Political and Economic Insecurity: Conflict, poor governance, and economic decline disrupt food systems and resource access, increasing malnutrition.
Gender Inequality: Unequal access to resources and education for women can negatively impact maternal and child health.
Environmental Issues: Climate change, natural disasters, and lack of productive land can disrupt food production and access.

Comparison of Causes: Undernutrition vs. Overnutrition

Malnutrition includes both undernutrition and overnutrition. Here is a comparison of their typical drivers:


Cause Category	Primary Drivers for Undernutrition	Primary Drivers for Overnutrition
Dietary	Lack of food, monotonous diet, insufficient protein, vitamins, or minerals.	Excess calorie consumption, high intake of energy-dense, low-nutrient foods, reliance on processed foods.
Health	Diseases (diarrhea, infections) causing nutrient loss or malabsorption; increased needs (growth, illness); anorexia; dysphagia.	Sedentary lifestyle, hormonal imbalances affecting appetite, chronic stress, anxiety.
Socioeconomic	Poverty limiting access to nutritious food; inadequate education on nutrition; food insecurity.	Economic disadvantage in developed nations leading to reliance on cheaper, less nutritious foods; aggressive marketing of junk food.

The Vicious Cycle of Malnutrition and Disease

Malnutrition and disease have a reciprocal relationship. Undernutrition weakens the body, making it more susceptible to infections. Infections, in turn, worsen malnutrition by reducing appetite and hindering nutrient absorption. This cycle is particularly harmful for vulnerable groups. Overnutrition also leads to chronic diseases, creating another health challenge. Breaking this cycle requires addressing both nutrition and health issues comprehensively.

Conclusion

Malnutrition is a complex issue driven by interconnected immediate, underlying, and basic causes. It affects people globally, encompassing both undernutrition and overnutrition. Effective solutions require more than just providing food; they demand a holistic approach addressing poverty, improving healthcare and education access, enhancing sanitation, and strengthening food security for all. For additional resources on global strategies, the World Health Organization offers information on combating all forms of malnutrition.

Frequently Asked Questions

Undernutrition is a form of malnutrition caused by a deficit of energy, protein, or other essential nutrients. Overnutrition, conversely, is caused by an excessive intake of energy and nutrients, leading to conditions like overweight and obesity.

Yes, it is possible to be both overweight and malnourished. This occurs when a person consumes excessive calories from energy-dense foods but lacks sufficient vitamins, minerals, and other essential nutrients, a condition sometimes called the “double burden of malnutrition”.

Poverty is a key driver of malnutrition because it limits a household’s ability to afford and access adequate quantities of nutritious food. It also reduces access to proper healthcare, education, and sanitation, which are critical for preventing disease and improving overall health.

Infectious diseases such as diarrhea, measles, and respiratory infections can cause malnutrition by reducing appetite, increasing the body’s nutrient needs, and interfering with nutrient absorption through vomiting or malabsorption. This creates a vicious cycle where malnutrition also increases susceptibility to disease.

Yes, older adults are at a higher risk of malnutrition for several reasons, including reduced appetite, difficulty eating due to dental problems or dysphagia, reduced mobility to procure food, social isolation, and chronic diseases.

Poor sanitation and hygiene lead to a higher prevalence of infectious diseases, particularly diarrheal illnesses, which can cause significant nutrient loss and hinder absorption. Access to clean water and sanitation is therefore a vital component of public health and nutrition.

Basic causes of malnutrition include broader issues such as political instability, gender inequality, inadequate education, and environmental problems like climate change and natural disasters. These factors control a society’s access to and distribution of resources.