What is wasting in malnutrition?
Wasting is a form of acute undernutrition, defined by a child's low weight-for-height compared to the World Health Organization (WHO) growth standards. It indicates recent and severe weight loss, or a failure to gain weight, and is often linked to a lack of adequate food and/or frequent illnesses. The term acute malnutrition is often used interchangeably with wasting. In adults, wasting is typically defined by a low Body Mass Index (BMI) or mid-upper arm circumference (MUAC). This condition is particularly dangerous because it severely weakens the immune system, making the affected individual highly susceptible to infection and increasing the risk of mortality. For young children, who are most vulnerable, wasting represents a critical indicator of a serious health and food insecurity crisis.
Causes of wasting
Wasting is not caused by a single factor but is the result of a complex interplay of immediate and underlying issues. The primary drivers are insufficient food intake and illness, which create a negative cycle of malnutrition and infection.
- Inadequate Dietary Intake: A simple lack of food or access to nutritious food is a key cause. This is especially prevalent in low-income countries and during times of food shortages, conflict, and climate disasters like droughts or floods. Poverty severely limits a family's ability to provide adequate and diverse food.
- Infectious Diseases: Frequent or prolonged illnesses, particularly those causing diarrhea, can rapidly lead to wasting. Diseases increase the body's energy needs while simultaneously decreasing appetite and nutrient absorption. Common childhood infections like pneumonia and measles are especially risky.
- Suboptimal Feeding Practices: For infants and young children, improper feeding practices contribute significantly to wasting. This includes a lack of exclusive breastfeeding for the first six months, or providing inappropriate and nutrient-poor complementary foods.
- Poor Sanitation and Hygiene: A lack of clean water and proper sanitation facilities increases exposure to disease-causing germs, fueling the cycle of infection and malnutrition. Unhygienic conditions and unsafe food preparation can lead to repeated bouts of illness.
- Underlying Social and Economic Factors: Beyond immediate causes, a host of other issues amplify the risk. These include poverty, limited access to healthcare, lack of maternal education, and environmental instability.
Types of wasting
Wasting is categorized into two levels of severity based on anthropometric measurements, primarily weight-for-height z-scores (WHZ) or mid-upper arm circumference (MUAC).
- Moderate Acute Malnutrition (MAM): This is a less severe form, defined by a weight-for-height z-score between -2 and -3 standard deviations of the median WHO growth standards, or a MUAC between 115mm and <125mm. Children with uncomplicated MAM often have a good appetite and can be treated in outpatient programs with specialized supplementary foods.
- Severe Acute Malnutrition (SAM): A life-threatening condition defined by a weight-for-height z-score below -3 standard deviations, a MUAC <115mm, or the presence of bilateral pitting edema. Children with SAM are at a very high risk of death and require urgent medical treatment, often in a hospital setting.
Key symptoms and diagnosis
Recognizing the signs of wasting is vital for early intervention. For children, the symptoms can include:
- Extreme thinness: The most obvious sign, presenting as visibly wasted fat and muscle tissue.
- Low energy: The child may be unusually tired, weak, and lethargic.
- Irritability and Apathy: Behavioral changes such as heightened anxiety or a lack of interest in surroundings and play.
- Faltering Growth: The child's growth curve on monitoring charts will flatten or drop, indicating a problem.
- Bilateral Pitting Edema: Swelling in both feet is a key clinical sign of severe acute malnutrition (kwashiorkor), confirmed by pressing a finger into the top of the foot for a few seconds.
Diagnosing wasting is a straightforward process involving a physical examination and specific measurements. For children, health workers measure height and weight to calculate weight-for-height z-scores, use a colored MUAC tape to measure the upper arm circumference, and check for bilateral edema. For adults, BMI and MUAC are the primary indicators. A blood test may be performed to check for specific micronutrient deficiencies.
Treatment for wasting
Treatment for wasting depends on its severity and whether there are complications. For most cases, a community-based approach can be highly effective.
Outpatient management (uncomplicated MAM and SAM)
- Ready-to-Use Therapeutic Foods (RUTFs): For children aged 6-59 months without medical complications but with a good appetite, RUTFs like Plumpy’Nut can be administered at home under supervision. These are high-energy, nutrient-dense pastes that are safe and do not require water for mixing, reducing the risk of contamination.
- Supplementary Feeding: For moderate wasting, ready-to-use supplementary foods (RUSFs) or fortified blended flours are used to prevent progression to SAM.
- Regular Monitoring: Weekly or bi-weekly follow-ups at a health center are essential to track the child’s weight gain and overall progress.
Inpatient management (complicated SAM)
- Hospital Admission: Children with SAM and medical complications (e.g., severe infections, fever, low appetite) require immediate inpatient care.
- 10-Step Protocol: The WHO outlines a 10-step protocol for inpatient management, focusing on two phases: stabilization and rehabilitation. This includes treating infections with antibiotics, correcting electrolyte imbalances, and gradually re-feeding with special therapeutic milks like F-75 and F-100.
- Addressing Underlying Issues: Concurrently, medical staff address associated problems such as dehydration, hypothermia, and hypoglycemia.
Preventing wasting
Prevention is the most effective long-term strategy for combating wasting and involves a multi-sectoral approach.
- Strengthening Health Systems: This includes ensuring pregnant women receive appropriate antenatal care and children have access to routine health services, immunizations, and vitamin A supplementation.
- Improving Diets: Promoting and supporting optimal infant and young child feeding (IYCF) practices is crucial. This includes exclusive breastfeeding for the first six months and introducing diverse, age-appropriate complementary foods thereafter.
- Enhancing Water, Sanitation, and Hygiene (WASH): Universal access to safe drinking water, sanitation facilities, and hygiene education is critical to breaking the cycle of infection and malnutrition.
- Social Protection: Programs like cash transfers and food assistance help financially vulnerable households purchase nutritious food, reducing the impact of poverty.
Wasting vs. stunting: A comparison
While both wasting and stunting are forms of undernutrition, they differ in their cause, duration, and effects on the body.
| Feature | Wasting | Stunting |
|---|---|---|
| Definition | Low weight-for-height | Low height-for-age |
| Indicates | Recent or rapid weight loss, acute undernutrition | Chronic or recurrent undernutrition |
| Cause | Inadequate food intake and/or recent illness | Long-term deprivation, poor socioeconomic conditions, chronic illness |
| Health Impact | Immediate, increased risk of death, weakened immune system | Long-term, irreversible physical and cognitive damage, poor developmental potential |
| Onset | Can appear and resolve relatively quickly with treatment | Develops slowly over a longer period |
| Vulnerability | Increases risk of acute illness and mortality | Reduces overall physical and cognitive development |
Some children can suffer from both wasting and stunting, a condition that carries a mortality risk comparable to severe wasting alone. This co-occurrence highlights the critical need for integrated nutrition strategies that address both acute and chronic undernutrition.
Conclusion
Wasting is a critical, life-threatening form of acute undernutrition that results from a severe lack of nutrients, often compounded by illness. While particularly prevalent in vulnerable populations, understanding its causes, types, and symptoms is essential for anyone involved in health or humanitarian work. Timely diagnosis using weight-for-height, MUAC, and edema checks is followed by treatment protocols that range from community-based care with therapeutic foods to inpatient management for complicated cases. However, the most sustainable solution lies in prevention. Strategies must focus on strengthening health systems, improving dietary practices, ensuring access to clean water, and supporting vulnerable families through social protection programs. By adopting comprehensive, integrated approaches, we can work towards a future where fewer children suffer from the devastating effects of wasting. For more information on this critical health issue, authoritative sources like the World Health Organization provide in-depth resources. World Health Organization (WHO)
