What is Wasting?
Wasting, or acute malnutrition, is defined as a low weight-for-height. It indicates a recent and severe episode of weight loss, or an inability to gain weight, often due to inadequate nutrient intake, malabsorption, or recurrent illness. Unlike stunting, which results from chronic malnutrition and affects height, wasting is more visible and poses an immediate, elevated risk of mortality, especially in young children. A child who is moderately or severely wasted has a weakened immune system, leaving them more susceptible to common infections and their complications.
How to Assess Wasting in Children
Early and accurate identification of wasting in children is vital for timely intervention. The World Health Organization (WHO) provides standardized protocols for nutritional assessment using a combination of methods.
Anthropometric Measurements for Children
Anthropometry is the science of measuring the human body. For children aged 6 to 59 months, the primary anthropometric tools for determining wasting are:
- Weight-for-Height Z-score (WHZ): This measure compares a child's weight to the reference weight for a child of the same height and sex. The result is expressed as a Z-score, or standard deviation, from the median of the WHO Child Growth Standards. A child with a WHZ below -2 SD is considered wasted, while a WHZ below -3 SD indicates severe wasting. This is considered the "gold-standard" for diagnosis at a facility level.
- Mid-Upper Arm Circumference (MUAC): This involves measuring the circumference of the child's upper arm using a color-coded tape. It is a simple, quick, and portable screening tool, making it ideal for community-level assessment. For children aged 6-59 months:
- MUAC < 115mm: indicates Severe Acute Malnutrition (SAM).
- MUAC between 115mm and <125mm: indicates Moderate Acute Malnutrition (MAM).
- Bilateral Pitting Edema: This is a third independent sign of severe wasting and involves testing for swelling in both feet. If a thumbprint indentation remains on both feet for a few seconds after pressure is applied, the child has edema, regardless of other anthropometric indicators, and should be referred for immediate treatment.
Clinical Signs in Children
Beyond measurements, healthcare providers look for visual cues of severe wasting, which can include:
- Visible severe wasting, such as loss of muscle bulk in the arms, thighs, and buttocks.
- Wrinkled, sagging skin.
- Fatigue and irritability.
- A diminished appetite.
How to Assess Wasting in Adults
While less frequently discussed, wasting can also be a serious concern in adults, particularly those with chronic diseases such as cancer, AIDS, or heart failure.
Anthropometric Measurements for Adults
- Body Mass Index (BMI): For adults, BMI (weight in kg / height in m²) is a primary indicator. A BMI below 18.5 is often considered underweight or wasted. Unintentional weight loss of more than 5-10% of body weight over a 3-6 month period is also a significant indicator of wasting syndrome.
- Mid-Upper Arm Circumference (MUAC): While most recognized for child screening, MUAC is also used for adults, especially in emergency settings, to assess muscle and fat mass. Specific cutoffs exist for adults but can vary by context and population.
Clinical Signs in Adults
Clinical signs of wasting in adults are often associated with underlying conditions and include:
- Visible muscle atrophy, particularly in the temples, clavicles, and thighs.
- Dry, flaky, or pale skin.
- Hair thinning or loss.
- Brittle, ridged, or spoon-shaped nails.
- Increased frequency of illness and slow wound healing.
- Persistent weakness and fatigue.
Comparison of Wasting Assessment Methods
To provide a clear overview, here is a comparison of the key methods used for determining wasting in children and adults.
| Feature | Method for Children (6-59 months) | Method for Adults | Notes |
|---|---|---|---|
| Primary Indicator | Weight-for-Height Z-score (WHZ) | Body Mass Index (BMI) | WHZ compares a child to a standard, while BMI is a general ratio for adults. |
| Screening Tool | Mid-Upper Arm Circumference (MUAC) | Mid-Upper Arm Circumference (MUAC) | MUAC tapes are color-coded for children; adult cutoffs vary. |
| Cutoff for Severe Wasting | WHZ < -3 SD; MUAC < 115mm | BMI < 18.5 (or significant weight loss) | Adult cutoffs for MUAC are typically higher and less standardized than for children. |
| Additional Sign | Bilateral Pitting Edema | Unintentional weight loss (>5-10% in 3-6 months) | Edema in children is a sign of severe malnutrition. Rapid, unexplained weight loss in adults suggests wasting. |
| Ease of Use | MUAC is very simple for community use. WHZ requires more training and equipment. | BMI is easily calculated. MUAC can be used for rapid assessment. | Simplicity is key for widespread screening in both groups. |
| Diagnostic Value | MUAC is an excellent predictor of mortality risk. WHZ is the gold standard for diagnosis at a health facility. | Both BMI and MUAC provide a good indication of nutritional status, but clinical context is essential. | In children, MUAC identifies high-risk cases for targeted treatment. |
Nutritional Management and Treatment
Once wasting is diagnosed, treatment must be initiated promptly, focusing on the underlying causes and providing targeted nutritional support. The approach differs based on severity and context.
- Ready-to-Use Therapeutic Food (RUTF): For many children with severe wasting without complications, RUTF offers a life-saving, home-based treatment option. RUTF is a high-energy, nutrient-dense paste that helps a child regain weight and health.
- Therapeutic Feeding Centers: Children with severe wasting and complications, or infants under six months, require inpatient care at a health facility for stabilization and careful feeding management.
- Dietary Adjustments for Adults: Treatment for adults with wasting syndrome often involves nutritional counseling to increase energy, protein, and fat intake through frequent, small, high-calorie meals. Supplementation may also be necessary.
- Addressing Underlying Conditions: For adults, treating the root cause (e.g., managing cancer, HIV, or heart disease) is a crucial part of reversing the wasting process.
Conclusion
Understanding how to determine wasting? is fundamental to combating acute malnutrition. Utilizing a combination of simple screening tools like MUAC and more definitive diagnostic measures like WHZ or BMI is key for effective intervention in both children and adults. Early detection through regular screening is essential, particularly in high-risk populations and emergency situations, as it dramatically improves the chances of a positive outcome. Ultimately, a multi-faceted approach involving anthropometry, clinical assessment, and targeted nutritional therapy is required to save lives and support the path to full recovery. A comprehensive approach also includes addressing the underlying social, economic, and environmental factors contributing to poor nutrition. For more in-depth information, you can consult UNICEF's resources on child wasting.
