What Is Wasting?
Wasting, also known as acute malnutrition, is a severe form of undernutrition resulting in low weight for height. It is often a sign of recent and drastic weight loss, indicating a significant energy deficit. This rapid loss of muscle and fat tissue can be caused by a period of insufficient food intake, prolonged illness, or both. It is particularly dangerous in young children, as it significantly increases their risk of mortality and can weaken their immune system, making them more vulnerable to disease. In adults, a similar condition called cachexia, or wasting syndrome, is often a serious complication of severe chronic diseases like cancer, heart disease, and AIDS.
Wasting vs. Stunting: Understanding the Difference
Wasting is distinct from other forms of undernutrition, such as stunting. While both are critical public health concerns, they result from different timelines of malnutrition.
| Characteristic | Wasting (Acute Malnutrition) | Stunting (Chronic Malnutrition) |
|---|---|---|
| Timing | Recent and severe onset | Chronic or recurrent, long-term |
| Physical Sign | Low weight for height (severe thinness) | Low height for age (short stature) |
| Underlying Cause | Acute food shortage, infectious disease | Long-term inadequate nutrition, poor hygiene, poverty |
| Impact | Increases risk of death, weakens immune system | Impairs physical and cognitive development |
| Reversibility | More easily corrected with proper nutrition | Often irreversible after early childhood |
How to Identify Wasting
Identifying wasting requires a combination of clinical observation and specific measurement techniques. These methods differ slightly for children and adults, but both focus on assessing weight, body composition, and signs of nutrient deficiency.
Identification in Children (Under 5 years)
- Mid-Upper Arm Circumference (MUAC): This is one of the most effective and widely used screening tools for childhood wasting, particularly in community and household settings. A color-coded MUAC tape is used to measure the circumference of the child's upper arm. A reading in the yellow zone indicates moderate acute malnutrition, while a reading in the red zone signifies severe acute malnutrition and requires immediate intervention.
- Weight-for-Height/Length: Comparing a child's weight to their height or length is a primary diagnostic method. The World Health Organization (WHO) defines wasting as a child whose weight-for-height falls two standard deviations below the median of the WHO growth standards. Severe wasting is defined as being three standard deviations below the median.
- Bilateral Oedema: A third key sign is nutritional oedema, or swelling in both feet. This can be checked by pressing a thumb gently on the top of both feet for three seconds. If a pitting indentation remains, oedema is present and is a sign of severe malnutrition.
- Visible Thinness: Physically appearing very thin is an obvious sign for caregivers to notice. This is a cue to seek professional medical assessment and measurements, even if the child seems otherwise active.
Identification in Adults
In adults, wasting is also identified through physical symptoms and key measurements. It is often linked to underlying chronic diseases.
- Unintentional Weight Loss: A significant and unexplained loss of more than 5% of body weight within 6 to 12 months is a primary indicator. This weight loss occurs even when the individual is not actively trying to lose weight.
- Low Body Mass Index (BMI): A BMI below 18.5 is considered a risk factor for malnutrition and a sign of wasting. For individuals already at risk, even a BMI under 20 is a concern.
- Muscle Loss: Noticeable reduction in muscle mass, known as muscle atrophy, can be observed. Signs include visibly smaller arms and legs, general weakness, and fatigue. Clothes, belts, and jewelry may become noticeably looser over time.
- Physical and Psychosocial Signs: Adults may also experience reduced appetite, low energy levels, poor concentration, and low mood or depression. Weakness, faintness, and apathy are also common.
Causes and Risk Factors of Wasting
Wasting is not just about a lack of food. It is a complex condition with multiple contributing factors, often intertwined with socioeconomic conditions and health status.
- Inadequate Nutritional Intake: This is the most direct cause, whether due to famine, poverty, or difficulty in eating. In children, inadequate complementary feeding after six months of age is a major factor.
- Frequent or Prolonged Illnesses: Chronic or recurrent infections, especially those causing diarrhea, can lead to nutrient malabsorption and increased energy expenditure. This is a major cause of wasting, particularly in children.
- Chronic Diseases: In adults, conditions like advanced cancer, heart failure, chronic obstructive pulmonary disease (COPD), and AIDS can trigger a wasting process known as cachexia. The body's metabolic rate increases, and appetite decreases, leading to significant muscle and fat loss.
- Socioeconomic Factors: Poverty, food insecurity, limited access to clean water and sanitation, and poor maternal health and nutrition all contribute to the risk of undernutrition.
- Psychological Factors: Mental health conditions such as depression and anorexia can lead to reduced appetite and nutritional intake. In the elderly, social isolation can also decrease motivation to eat and cook.
The Role of Health Professionals
When wasting is suspected, a healthcare professional can provide a formal diagnosis and treatment plan. This may involve a more detailed assessment than what is possible at home.
Diagnostic Procedures
- Comprehensive Screening: Healthcare professionals often use standardized tools like the Malnutrition Universal Screening Tool (MUST) for adults to systematically assess risk.
- Medical History and Examination: A thorough history, including recent weight changes, appetite, and any chronic conditions, is taken. A physical exam confirms visible signs of wasting and assesses muscle mass.
- Blood Tests: These can check for specific micronutrient deficiencies, which often accompany protein-energy undernutrition. Blood tests can also help identify any underlying medical conditions contributing to the wasting.
- Further Investigations: In complex cases, imaging like an MRI or specialized muscle and nerve tests may be needed to pinpoint the cause of muscle atrophy.
How to Respond to a Wasting Diagnosis
Once wasting is identified, a multi-faceted treatment approach is necessary. The specific plan will depend on the severity and underlying cause, but generally involves nutritional rehabilitation and addressing any medical issues.
Action Steps
- Nutritional Support: Treatment often involves high-calorie nutritional formulas or supplements designed to replenish lost nutrients. In cases of severe acute malnutrition in children, ready-to-use therapeutic food (RUTF) is used.
- Treat Underlying Conditions: It is essential to manage any underlying infections or chronic diseases that are contributing to the wasting. This may involve antibiotics or other specific medical treatments.
- Medical Supervision: For severe cases, especially in children, initial refeeding is done under close medical observation to prevent complications like refeeding syndrome.
- Psycho-social Support: Addressing issues like appetite loss, depression, or difficulty preparing food is a crucial part of recovery, particularly in adults and caregivers.
- Long-Term Prevention: Beyond treatment, long-term strategies focus on improving access to nutritious food, promoting healthy eating habits, and ensuring access to clean water and sanitation to prevent recurrence.
Conclusion Learning how to identify wasting is a critical first step in addressing this life-threatening condition. By recognizing the physical signs of severe weight loss, and utilizing objective measurements like MUAC and weight-for-height, both caregivers and health professionals can initiate timely intervention. A successful response involves not only treating the symptoms with nutritional and medical support but also addressing the underlying causes, whether they are linked to illness, economic hardship, or inadequate nutrient intake. Early detection and a comprehensive approach to treatment offer the best chance for recovery and improved health outcomes, especially for vulnerable populations.
For more detailed guidance on the prevention and management of wasting in infants and children, consult the WHO guideline on the prevention and management of wasting.
