What is it called when people don't receive enough nutrients? Malnutrition Explained

December 25, 2025 •

4 min read

According to the World Health Organization, nearly half of deaths among children under 5 years of age are linked to undernutrition, a severe form of what is called when people don't receive enough nutrients. This condition has serious and lasting impacts on individuals, families, and global communities, emphasizing the critical importance of understanding and addressing nutritional deficits.

Quick Summary

Malnutrition is the overarching term for deficiencies, excesses, or imbalances in nutrient intake. Undernutrition, a primary form, occurs when someone doesn't get enough calories, protein, or micronutrients like vitamins and minerals, leading to significant health issues. Both inadequate diet and medical conditions that impair nutrient absorption are common causes.

Key Points

Malnutrition is the overarching term: This describes any imbalance in nutrient intake, which can mean not enough (undernutrition) or too much (overnutrition).
Undernutrition is a primary type: It refers to a deficiency in calories, protein, or micronutrients and is often associated with food scarcity and poverty.
Types of undernutrition include wasting and stunting: Wasting is low weight-for-height, indicating severe recent weight loss, while stunting is low height-for-age, resulting from chronic undernutrition.
Micronutrient deficiency is 'hidden hunger': This involves a lack of essential vitamins and minerals and can occur even if overall calorie intake is sufficient.
Causes range from societal to personal: Factors include poverty, food insecurity, infectious diseases, and medical conditions that affect nutrient absorption.
Diagnosis involves physical exams and lab tests: Healthcare professionals assess weight, height, BMI, and can use blood tests to identify specific deficiencies.
Prevention requires access and education: A balanced, varied diet is crucial, supported by programs and policies that address food security and nutritional knowledge.

Malnutrition: The Broad Term for Nutrient Imbalance

When people don't receive enough nutrients, the medical and scientific community refers to this condition as malnutrition. This is an all-encompassing term that doesn't just refer to a lack of food but rather an imbalance of essential nutrients, which can include deficiencies, excesses, or the incorrect proportion of nutrients. While the common perception of malnutrition involves a person not getting enough food (undernutrition), the term also includes overnutrition, which is an overconsumption of certain nutrients leading to obesity.

The Two Main Forms of Malnutrition

To better understand malnutrition, it is essential to distinguish between its two primary forms:

Undernutrition: This occurs when a person is deficient in calories, protein, or other essential nutrients. It is the more widely recognized form of malnutrition and can manifest in several ways.
Overnutrition: This is the result of consuming an excess of certain nutrients or too many calories, often leading to obesity and other health issues. The 'double burden of malnutrition' exists where both undernutrition and overnutrition coexist within the same country or even the same community.

Diving Deeper into Undernutrition

Undernutrition is a complex condition with several sub-types, each with distinct features:

Wasting: Characterized by low weight-for-height, it often indicates recent and severe weight loss, usually from not eating enough food or an infectious disease like diarrhea. Children who are severely wasted have a high risk of death if not treated.
Stunting: Defined as low height-for-age, stunting is the result of long-term or recurring undernutrition. It typically begins early in life and is linked to poor socioeconomic conditions and frequent illness. This can prevent children from reaching their full physical and cognitive potential.
Underweight: This refers to low weight-for-age and can be a combination of both wasting and stunting.
Micronutrient Deficiencies: Also known as 'hidden hunger,' this refers to a lack of essential vitamins and minerals, such as iodine, vitamin A, and iron, which are crucial for proper growth and development.

Causes of Malnutrition

Malnutrition, particularly undernutrition, stems from a variety of immediate, underlying, and basic causes.

Inadequate Dietary Intake: This is the most direct cause. It can result from limited access to nutritious food due to poverty, food shortages, or specific medical conditions that make eating difficult, such as nausea or swallowing issues. Mental health conditions like anorexia and depression can also contribute.
Diseases and Malabsorption: Certain illnesses, particularly infectious ones like diarrhea, HIV/AIDS, and respiratory infections, can lead to undernutrition. This happens because diseases can increase nutrient requirements, decrease appetite, or impair the body's ability to absorb nutrients. Malabsorption disorders like Crohn's disease also prevent nutrient uptake.
Socioeconomic Factors: Poverty, war, and civil unrest are major drivers of malnutrition globally, as they disrupt food access and distribution systems. Lack of nutrition education is also a significant contributor.
Physiological Factors: Certain life stages, such as infancy, childhood, pregnancy, and old age, carry a higher risk of malnutrition due to greater or altered nutritional needs.

Comparison of Undernutrition and Overnutrition

To provide clarity, here is a comparison table outlining the key differences between the two primary forms of malnutrition.


Aspect	Undernutrition	Overnutrition
Primary Cause	Insufficient intake of calories, protein, or micronutrients.	Excessive consumption of calories or specific nutrients.
Common Manifestations	Wasting, stunting, low body weight, micronutrient deficiencies.	Overweight, obesity, high body mass index (BMI).
Common Associated Symptoms	Fatigue, weakness, impaired immune function, stunted growth, wasting of muscle and fat tissue.	High blood pressure, insulin resistance, higher risk of diet-related noncommunicable diseases (NCDs).
Risk Factors	Poverty, food insecurity, infectious diseases, malabsorption disorders.	Sedentary lifestyle, high intake of energy-dense foods, hormonal imbalances.
Affected Populations	Disadvantaged communities, infants, children, the elderly, chronically ill individuals.	Can affect anyone, increasingly prevalent in developed countries and urban areas of developing countries.

Diagnosis, Treatment, and Prevention

Diagnosing malnutrition involves a physical exam, assessing height, weight, and BMI, along with blood tests to check for specific nutrient deficiencies like iron or vitamins. Treatment depends on the severity and cause. For undernutrition, this can involve nutritional supplements and, in severe cases, specialized refeeding programs under medical supervision. Overnutrition is often managed with diet and lifestyle changes to achieve healthy weight loss.

Prevention is key and requires a multi-faceted approach. Globally, this involves improving access to nutritious food and providing nutritional education. At an individual level, a balanced and varied diet is crucial. For specific at-risk populations like children and the elderly, tailored support is essential to ensure adequate nutrition. For example, promoting exclusive breastfeeding for the first six months is critical for infant health.

Conclusion

In summary, the term for not receiving enough nutrients is malnutrition, a condition that encompasses both undernutrition and overnutrition. While undernutrition is often associated with a lack of food and is particularly devastating for children, malnutrition also includes imbalances caused by poor diet quality or overconsumption. Addressing this global health challenge requires a combination of adequate food access, education, and targeted interventions to ensure that everyone, regardless of age or circumstance, can achieve proper nutrition for a healthy and fulfilling life. Understanding the various forms, causes, and consequences is the first step toward effective prevention and treatment.

World Health Organization Fact Sheet on Malnutrition

Frequently Asked Questions

The primary medical term is malnutrition, which broadly covers deficiencies, excesses, and imbalances in a person's nutrient intake. The specific type where intake is insufficient is called undernutrition.

Yes, it is possible to be overweight and malnourished simultaneously. This condition is sometimes called the 'double burden of malnutrition,' where a person consumes an excess of calories but still lacks essential vitamins and minerals.

Common signs of undernutrition include unintentional weight loss, fatigue, weakness, weakened immune function, slow wound healing, and in children, delayed growth and development.

Malnutrition is diagnosed through a combination of a physical examination, assessing height, weight, and BMI, and often by ordering blood tests to check for specific nutrient deficiencies.

Micronutrient deficiencies can be caused by a poor-quality diet lacking variety, reduced nutrient absorption due to certain medical conditions, increased nutrient requirements during specific life stages, or genetic factors.

Treatment varies by the type and severity of malnutrition. For undernutrition, it often involves nutritional supplements or supervised refeeding. For overnutrition, treatment focuses on dietary changes, weight management, and lifestyle adjustments.

Certain groups are at higher risk, including infants, young children, pregnant women, the elderly, and individuals with chronic illnesses, due to increased nutritional needs or factors affecting appetite and absorption.