What are the diseases caused by nutritional imbalance?

October 18, 2025 •

4 min read

Globally, almost half of the deaths among children under five years old are linked to undernutrition. This startling statistic highlights the severe health consequences of a nutritional imbalance, which involves an inadequate, excessive, or disproportionate intake of essential nutrients.

Quick Summary

Nutritional imbalance, or malnutrition, results from either nutrient deficiencies or excesses and leads to a wide range of health issues. This overview details the various diseases caused by inadequate or overabundant intake of macronutrients and micronutrients.

Key Points

Undernutrition vs. Overnutrition: Nutritional imbalance includes both underconsumption (deficiency) and overconsumption (excess) of nutrients, both of which can cause serious health problems.
Macronutrient-Related Diseases: Inadequate protein and calories can cause severe wasting conditions like marasmus and kwashiorkor, while excess intake contributes to obesity, Type 2 diabetes, and cardiovascular diseases.
Micronutrient Deficiencies: Lack of essential vitamins and minerals leads to specific diseases, such as scurvy (Vitamin C), rickets (Vitamin D), anemia (Iron), and goiter (Iodine).
Chronic Illness Links: Long-term nutritional imbalances are significant risk factors for chronic noncommunicable diseases, including heart disease, stroke, and certain cancers.
Preventative Measures: A balanced and diverse diet is key to preventing malnutrition in all its forms. Addressing underlying issues like poverty and providing nutritional education are crucial strategies.

The Broad Spectrum of Nutritional Imbalance

Nutritional imbalance, or malnutrition, is a comprehensive term that describes a mismatch between the body's nutrient needs and its actual intake. This includes two primary categories: undernutrition and overnutrition. Undernutrition results from not getting enough of certain nutrients, while overnutrition occurs from consuming excessive amounts. This imbalance can affect both macronutrients (proteins, fats, and carbohydrates) and micronutrients (vitamins and minerals), leading to a wide array of health problems.

Diseases Caused by Macronutrient Imbalances

Macronutrients provide the body with energy and are crucial for growth and maintenance. Imbalances in these can have significant and visible consequences.

Macronutrient Undernutrition

Protein-Energy Malnutrition (PEM): This severe condition is often caused by a diet lacking sufficient protein and calories. The two classic forms are marasmus and kwashiorkor.
- Marasmus: Resulting from extreme deprivation of both energy and protein, marasmus leads to severe wasting of muscle and fat, leaving infants appearing exceptionally underweight.
- Kwashiorkor: Caused by a severe protein deficiency despite adequate calorie intake, this condition often results in a distended abdomen due to fluid retention (edema).
Essential Fatty Acid Deficiency: Inadequate intake of essential omega-3 and omega-6 fatty acids can lead to poor wound healing, increased susceptibility to infections, and skin issues.

Macronutrient Overnutrition

Excessive intake of macronutrients, particularly processed carbohydrates and unhealthy fats, is a primary driver of modern chronic diseases.

Obesity: The storage of excess energy as fat can lead to overweight and obesity, a major public health concern associated with chronic inflammation and metabolic disorders.
Type 2 Diabetes: Diets high in refined sugars and fats can lead to insulin resistance, a key factor in the development of type 2 diabetes.
Cardiovascular Disease: Excessive consumption of saturated and trans fats, high sodium, and refined sugars contributes to conditions like atherosclerosis, hypertension, and heart attacks.

Diseases Caused by Micronutrient Imbalances

Even small deficiencies or excesses of vitamins and minerals can severely disrupt bodily functions.

Vitamin Deficiencies

Scurvy (Vitamin C): Causes include bleeding gums, impaired wound healing, and internal bleeding.
Rickets and Osteomalacia (Vitamin D): Leads to inadequate bone mineralization. In children, it causes bowed legs (rickets), while in adults, it leads to soft bones (osteomalacia).
Night Blindness (Vitamin A): The leading cause of preventable blindness in children, it can progress to total blindness if left untreated.
Beriberi (Thiamin/Vitamin B1): A B-vitamin deficiency that can result in nerve damage, cardiovascular issues, and altered muscle coordination.
Pellagra (Niacin/Vitamin B3): Characterized by the "3 Ds": dermatitis, diarrhea, and dementia.
Anemia (Vitamin B12 or Folate): Deficiency can lead to megaloblastic anemia, which causes fatigue and weakness.

Mineral Deficiencies

Iron-Deficiency Anemia: The most prevalent nutritional deficiency worldwide, resulting in fatigue, weakness, and decreased work output.
Iodine Deficiency Disorders (IDD): Causes include goiter (enlarged thyroid gland), hypothyroidism, and, in severe cases during pregnancy, cretinism and mental retardation in offspring.
Zinc Deficiency: Can cause skin lesions, weakened immune function, diarrhea, and impaired growth and development.

The Chronic and Complex Consequences

Nutritional imbalance can contribute to long-term systemic inflammation and affect multiple organ systems, especially in the context of overnutrition. Unhealthy diets high in processed foods, unhealthy fats, and added sugars are a significant risk factor for chronic conditions beyond metabolic disorders, including inflammatory bowel disease, certain cancers, and cognitive decline. Chronic undernutrition also weakens the immune system, making individuals more vulnerable to infections.

Comparison of Macronutrient Imbalance Effects


Feature	Macronutrient Undernutrition	Macronutrient Overnutrition
Underlying Cause	Insufficient intake of protein, fats, and carbohydrates, often linked to food scarcity, poverty, or eating disorders.	Excessive intake of calories from protein, fats, and carbohydrates, often from processed foods.
Primary Manifestations	Severe muscle and fat wasting, stunted growth, edema, impaired organ function.	Obesity, excessive body fat accumulation, and subsequent weight gain.
Associated Diseases	Marasmus, Kwashiorkor, anemia, increased infection susceptibility, and poor wound healing.	Type 2 diabetes, cardiovascular disease (hypertension, atherosclerosis), metabolic syndrome, and certain cancers.
Common Physical Signs	Frail appearance, low body temperature, low blood pressure, pale skin, hair loss.	High blood pressure, large waist circumference, symptoms of insulin resistance.

Conclusion

The range of diseases caused by nutritional imbalance is extensive and impacts health at every life stage. Both a lack of essential nutrients and an excess of calories, unhealthy fats, and sugars can lead to serious health conditions, from acute deficiencies like scurvy and goiter to chronic issues such as obesity, diabetes, and heart disease. Preventing these conditions requires addressing the root causes of malnutrition, including lack of education, poverty, and environmental factors. Promoting a varied and balanced diet, rich in whole foods and appropriate for individual needs, remains the most effective strategy for ensuring long-term health and well-being. For further reading on nutritional health, the World Health Organization (WHO) offers extensive resources on healthy eating guidelines.

Frequently Asked Questions

Marasmus results from a severe deficiency of both calories and protein, leading to extreme wasting of fat and muscle. Kwashiorkor is primarily caused by a severe protein deficiency despite adequate calorie intake, often characterized by edema or a swollen belly.

Yes. This is a form of malnutrition known as overnutrition. A person can consume more than enough calories to meet their energy needs but still be deficient in key micronutrients like vitamins and minerals due to an unbalanced diet.

Early signs can vary widely depending on the nutrient but may include fatigue, headaches, weakened immunity, poor vision (like night blindness for Vitamin A), or skin issues.

Both undernutrition and specific micronutrient deficiencies can impair immune function, increasing a person's vulnerability to infections. Zinc deficiency, for example, is directly linked to cell-mediated immune dysfunction.

While supplementation can be vital in treating severe deficiencies, especially during critical life stages like pregnancy, a food-based approach with a balanced, diverse diet is generally the most sustainable strategy for long-term health.

Overnutrition, often leading to obesity, is a major risk factor for noncommunicable diseases such as type 2 diabetes, hypertension, cardiovascular disease (e.g., atherosclerosis), and certain cancers.

Iodine deficiency can cause an enlarged thyroid gland (goiter) and hypothyroidism. During pregnancy, it can lead to severe developmental issues in the fetus, including mental retardation and cretinism.