I. Investigation into the Causes of Malnutrition

1. Insufficient Food Intake: This may be due to poverty, which makes it impossible to access nutritious and affordable food; or it could be a situation of food insecurity, such as living in a food desert area where it is difficult to obtain sufficient and diverse food sources.

2. Inaccessibility of Nutritious Food: Some regions or populations, due to economic, geographical, and other factors, lack the means to access appropriate nutritious food.

3. Disordered Eating Patterns: For example, eating disorders like anorexia nervosa and bulimia can severely disrupt the balance between normal food intake and nutrient absorption.

4. Interference from Health Conditions: Gastrointestinal diseases such as Crohn's disease and celiac disease, chronic infections, liver diseases, and other chronic illnesses can impede the body's normal absorption and utilization of nutrients. In addition, special cases such as cancer patients and those with end-stage renal disease undergoing dialysis are also prone to malnutrition due to abnormal body metabolism and the effects of treatment.

II. Analysis of the Types of Malnutrition

1. Stunted Growth in Children Under Five: This is the result of long-term malnutrition and a lack of sufficient food and medical care. It is a growth disorder that gradually develops in children under five. The height-for-age index can be used to determine whether a child is stunted. This type of malnutrition can lead to cognitive impairments, such as delayed motor skills development, poor brain function, and low academic performance.

2. Wasting in Children Under Five: Refers to a situation where a child's weight is significantly lower than their height, usually caused by acute food shortages or diseases. It is also known as acute malnutrition and occurs rapidly. It can be measured by the weight-for-height index or mid-upper arm circumference (MUAC). The symptoms can be mild to severe and increase the risk of premature death in children.

3. Protein-Energy Malnutrition (PEM): Arises from a lack of calorie and protein intake. It may result from unstable food supplies and is also common among cancer patients, those with end-stage renal disease on dialysis, and other patients with chronic diseases. It has two manifestations: marasmus (resulting in severe weight loss) and kwashiorkor (causing edema and fatty liver).

4. Micronutrient Deficiency: Means that the human body cannot obtain sufficient essential vitamins or minerals. A monotonous diet or poor nutrient absorption is the main cause. Common deficiencies include iron, zinc, iodine, vitamin D, vitamin A, or vitamin C, which can lead to fatigue, muscle weakness, or a weakened immune system. Maintaining a balanced diet with a variety of fruits, vegetables, and protein sources helps prevent micronutrient deficiencies.

5. Overnutrition: Different from the commonly perceived malnutrition, this occurs when excessive amounts of nutrients, especially fats, sugars, and calories, are consumed. It significantly increases the risk of health problems such as obesity, heart disease, type 2 diabetes, stroke, and certain cancers. Through a balanced diet and the guidance of a dietitian, it is possible to develop a dietary plan that meets one's body needs and avoid overnutrition.

6. Secondary Malnutrition: Caused by underlying health problems such as gastrointestinal diseases, liver diseases, or infections that prevent the body from normally absorbing or using nutrients. It can occur even with a balanced diet and may be accompanied by symptoms such as nausea, vomiting, or loss of appetite.

III. Warning Signs of Malnutrition Symptoms

IV. Diagnosis Process of Malnutrition

V. Treatment Strategies for Malnutrition

VI. Prevention Measures for Malnutrition

VII. Complications and Risks of Malnutrition