What is overnourished and undernourished?

December 29, 2025 •

4 min read

According to the World Health Organization (WHO), malnutrition, in all its forms, includes both undernutrition (wasting, stunting, underweight, and micronutrient deficiencies) and overnutrition (overweight and obesity). While often mistaken as a problem of scarcity, malnutrition is a serious and widespread global health issue that can affect anyone, regardless of their weight or economic status.

Quick Summary

Overnourishment and undernourishment are forms of malnutrition involving an excess or deficiency of nutrients, respectively. This article explains the distinctions between the two, exploring their causes, symptoms, and health risks to shed light on how they impact the body differently.

Key Points

Malnutrition is a broad term: It encompasses both undernutrition (deficiency) and overnutrition (excess) and is not solely about starvation.
Undernourishment is nutrient deficiency: It is caused by insufficient intake or absorption of calories, proteins, vitamins, and minerals, leading to health issues like wasting, stunting, and a weakened immune system.
Overnourishment is nutrient excess: It results from consistently consuming more nutrients, especially calories from unhealthy foods, than the body needs, often leading to overweight, obesity, and chronic diseases.
The 'double burden' is a modern challenge: It describes communities facing both undernutrition and overnutrition simultaneously due to shifting dietary patterns.
Both have severe consequences: Long-term undernutrition can cause permanent developmental problems, while overnutrition increases the risk of metabolic syndrome, heart disease, and diabetes.
Prevention requires balance: A balanced diet with adequate physical activity is the best strategy to prevent all forms of malnutrition.
Early intervention is crucial: Addressing nutritional imbalances early can prevent or mitigate severe, and sometimes irreversible, long-term health effects.

Understanding the Concept of Malnutrition

Malnutrition is a broad term describing an imbalance in a person's intake of energy and/or nutrients. It's not limited to a lack of food; it can also result from a diet with too much of certain nutrients. Malnutrition can manifest in various ways, including undernutrition, overnutrition, and micronutrient-related malnutrition, such as vitamin or mineral deficiencies. Addressing these imbalances is crucial for maintaining proper bodily function, growth, and overall health throughout a person's life.

What Does Undernourished Mean?

Undernutrition refers to a state of nutrient deficiency, which can arise from a lack of calories (protein-energy undernutrition) or insufficient vitamins and minerals (micronutrient undernutrition). This can happen due to inadequate dietary intake, malabsorption issues, or medical conditions that increase the body's energy needs.

Symptoms of undernutrition include:

Visible Wasting: Severe weight loss and prominent bones due to the body breaking down fat and muscle tissue for energy.
Stunted Growth: Particularly in children, chronic undernutrition can lead to low height for age, hindering physical and cognitive development.
Weakened Immune System: An undernourished body is less capable of fighting off infections and recovering from illness.
Chronic Fatigue and Weakness: Low energy levels are a common complaint as the body lacks the fuel needed for daily activities.
Edema: Swelling in the abdomen, face, or legs, which can occur in severe cases of protein deficiency.

What Does Overnourished Mean?

Overnutrition occurs when a person consumes more nutrients than the body requires over an extended period. It is often associated with the excessive consumption of energy-dense foods high in fats, sugars, and salt, but low in essential vitamins and minerals. While obesity is the most common and visible result of overnutrition, it's possible to be overweight yet still be deficient in certain micronutrients.

Symptoms and consequences of overnutrition include:

Obesity: Excessive accumulation of body fat that can lead to numerous health problems.
Metabolic Syndrome: A cluster of conditions, including high blood pressure, insulin resistance, and abnormal cholesterol levels, that increase the risk of heart disease and diabetes.
Chronic Noncommunicable Diseases (NCDs): Increased risk of cardiovascular diseases, type 2 diabetes, and certain types of cancer.
Micronutrient Toxicity: In rare cases, excessive intake of specific vitamin and mineral supplements can lead to toxic effects.

Comparison of Overnourishment vs. Undernourishment

Both overnourishment and undernourishment fall under the umbrella of malnutrition, but they have distinct causes, symptoms, and health consequences. The following table provides a clear comparison:


Feature	Undernourished (Deficiency)	Overnourished (Excess)
Primary Cause	Inadequate intake, malabsorption, or increased need of energy and nutrients.	Excessive intake of energy and nutrients, often from poor-quality, energy-dense foods.
Associated Weight Status	Underweight, wasting, and stunting are common, though some may be of normal weight with micronutrient deficiencies.	Overweight and obesity are typical, but micronutrient deficiencies can coexist.
Symptoms	Weight loss, fatigue, apathy, stunted growth, weakened immunity, edema.	Weight gain, high blood pressure, insulin resistance, risk of chronic diseases.
Health Risks	Increased susceptibility to infections, impaired organ function, developmental issues, death.	Cardiovascular disease, diabetes, certain cancers, metabolic disorders.
Underlying Factors	Poverty, food insecurity, access issues, certain chronic diseases, eating disorders.	Sedentary lifestyle, availability of cheap energy-dense foods, psychological factors, hormonal imbalances.
Treatment Focus	Increasing intake of calories, protein, and micronutrients, often with medical supervision for severe cases.	Weight management, dietary modifications (reducing fats and sugars), and increased physical activity.

The Double Burden of Malnutrition

The 'double burden of malnutrition' is a phenomenon where undernutrition and overnutrition coexist within the same country, community, or even the same household. For example, a child may suffer from stunted growth due to chronic undernutrition while an adult in the same family is obese. This paradox is often seen in low- and middle-income countries that are undergoing rapid dietary shifts, where highly processed, inexpensive foods displace traditional, more nutritious diets.

Preventing and Addressing Nutritional Imbalances

Prevention and treatment for both conditions require comprehensive strategies. For undernutrition, particularly in vulnerable populations like children and the elderly, ensuring access to a balanced diet and addressing underlying health issues is paramount. In cases of overnutrition, prevention centers on promoting healthier dietary patterns and increased physical activity, moving away from high-calorie, low-nutrient foods. Public health policies, nutritional education, and addressing socioeconomic disparities are key to tackling both sides of the malnutrition spectrum. Early intervention is crucial, as some effects of long-term nutritional imbalances, like stunted growth or chronic diseases, can be irreversible.

Conclusion

Being overnourished or undernourished are two sides of the same coin: malnutrition. Both involve an imbalance of nutrients and carry significant health risks. While undernutrition stems from a deficiency of essential nutrients, overnutrition results from a prolonged excess. Understanding the distinction is vital for accurate diagnosis and effective public health initiatives. Ultimately, a balanced and varied diet, along with regular physical activity, is the best defense against all forms of malnutrition, promoting overall wellness and long-term health.

Optional: For more information on preventing nutritional deficiencies, you can consult the World Health Organization's 'Healthy diet' fact sheet.

Frequently Asked Questions

Yes, this is known as the 'double burden of malnutrition'. A person can be overweight or obese due to excessive calorie intake but still be undernourished if their diet lacks essential vitamins and minerals.

PEM is a form of undernutrition caused by a severe, prolonged deficiency of both protein and calories. It includes conditions like marasmus and kwashiorkor, which result in muscle wasting and stunted growth.

Early signs can include fatigue, unintentional weight loss, frequent infections, loss of appetite, and changes in hair or skin texture.

No, while overweight and obesity are common signs, overnutrition is defined as an excess of nutrients. This can also include consuming too much of a specific micronutrient, which can be toxic.

Socioeconomic status is a significant factor in malnutrition. Poverty can lead to undernutrition due to lack of access to nutritious food. In developed countries, lower-income areas often have easier access to high-calorie, low-nutrient fast food, contributing to overnutrition.

Preventing malnutrition involves eating a balanced diet rich in fruits, vegetables, lean protein, and whole grains. Limiting intake of free sugars, saturated fats, and salt is also key for avoiding overnutrition.

Both undernutrition and overnutrition can have long-lasting effects on a child's development. Undernutrition can cause stunting and delayed cognitive development, while overnutrition in childhood can increase the risk of obesity and related chronic diseases later in life.