What Defines Wasting?: Understanding This Severe Form of Malnutrition

Globally in 2022, an estimated 45 million children under 5 were affected by wasting. What defines wasting is a dangerously low weight for a person's height, indicating recent and severe weight loss or a failure to gain weight, often due to inadequate nutrition and illness.

Quick Summary

Wasting is a life-threatening form of acute malnutrition characterized by a low weight-for-height. It indicates recent, rapid weight loss resulting from insufficient food intake, frequent illnesses, or a combination of factors, primarily affecting children.

Key Points

• Official Definition: Wasting is officially defined by the World Health Organization as a low weight-for-height, indicating acute and often rapid undernutrition.

• Measurement Methods: In addition to using a weight-for-height z-score, it can be diagnosed with a mid-upper-arm circumference (MUAC) measurement, particularly for children.

• Key Causes: Causes include a combination of insufficient food intake, infectious diseases like diarrhea and measles, and poor care practices.

• Severe Form: Severe acute malnutrition (SAM), the most lethal form of wasting, is identified by a very low weight-for-height, extremely low MUAC, and/or bilateral pitting edema.

• Differentiating from Stunting: While wasting is a measure of acute nutritional deficiency, stunting is a measure of chronic, long-term undernutrition.

• Lifesaving Treatment: Treatment for severe wasting typically involves therapeutic feeding with ready-to-use therapeutic food (RUTF) and management of infections.

• Prevention is Key: Prevention strategies focus on maternal nutrition, exclusive breastfeeding, improved sanitation, and addressing food insecurity.

The Technical Definition of Wasting

The World Health Organization (WHO) defines wasting, also known as acute malnutrition, using anthropometric measurements. For children under five, wasting is identified when their weight-for-height z-score (WHZ) is more than two standard deviations below the median of the WHO Child Growth Standards. The mid-upper-arm circumference (MUAC) can also be used, with a measurement below 125mm indicating acute malnutrition for children aged 6 to 59 months. Severe acute malnutrition (SAM) is defined by a WHZ below -3 SD, MUAC less than 115mm, and/or the presence of bilateral pitting edema. Bilateral pitting edema, a swelling caused by fluid retention, is a sign of severe acute malnutrition.

Wasting Versus Stunting: Understanding the Differences

Wasting and stunting are different forms of undernutrition. Wasting is a measure of acute malnutrition from recent nutritional deficits or illness and can be rapidly corrected. Stunting is chronic malnutrition, defined by low height-for-age, resulting from long-term undernutrition and infections. Stunting is more difficult to reverse and can cause permanent impairments. Episodes of wasting can increase the risk of stunting, and having both simultaneously significantly raises the risk of death. Prevention needs to address both.

Feature	Wasting (Acute Malnutrition)	Stunting (Chronic Malnutrition)
Definition	Low weight-for-height.	Low height-for-age.
Timing	Recent and severe weight loss or failure to gain weight.	Long-term or recurrent undernutrition.
Primary Cause	Acute issues like illness (e.g., diarrhea) or food shortage.	Chronic issues like poor feeding, recurring infections, and poverty.
Measurement	Weight-for-height z-score (WHZ) or MUAC.	Height-for-age z-score (HAZ).
Reversibility	Often reversible with targeted nutritional and medical care.	More difficult to reverse, with long-term impacts.
Immediate Risk	High risk of mortality and severe illness.	Impaired physical and cognitive potential.

Causes and Consequences of Wasting

Wasting is caused by a mix of factors, especially in vulnerable areas. Key causes include inadequate food intake due to poverty or food insecurity, frequent illnesses like diarrhea and malaria, poor feeding practices, and maternal malnutrition during pregnancy. Wasting severely weakens the immune system, increasing the risk of death and impacting physical and cognitive development.

Management, Treatment, and Prevention

Treating wasting, especially severe cases, requires urgent, specialized care. Stabilization includes treating complications like hypoglycemia and infections. Rehabilitation feeding uses therapeutic foods like RUTF for uncomplicated cases or specialized formulas (F-75, F-100) in facilities. Micronutrient supplements are also crucial.

Prevention focuses on maternal nutrition, optimal infant feeding (exclusive breastfeeding and complementary feeding), strengthening health and hygiene systems, and addressing poverty and food insecurity.

Conclusion

Wasting is a critical form of acute undernutrition defined by dangerously low weight for height, distinct from stunting. It stems from insufficient food, illness, and poor care, leading to a high risk of death and long-term health problems. Effective treatment and prevention through focusing on maternal health, infant feeding, and strengthening public health systems are key to combating this crisis. Understanding what defines wasting is vital for effective public health responses.

What Defines Wasting: A Closer Look

Wasting requires urgent attention but is treatable and preventable. A multi-sectoral approach addressing both symptoms and underlying causes is necessary. Differentiating between acute wasting and chronic stunting is crucial for effective interventions. More information on global nutrition strategies is available from the World Health Organization (WHO) website.

Frequently Asked Questions

What is the primary difference between wasting and stunting?

The main difference is the duration of malnutrition. Wasting is a measure of acute, or recent, malnutrition (low weight-for-height), whereas stunting is a measure of chronic, or long-term, malnutrition (low height-for-age).

How is wasting measured in children?

In children, wasting is measured using the weight-for-height z-score (WHZ), which compares a child's weight to the standard weight for a child of the same height and sex. A mid-upper-arm circumference (MUAC) measurement is also commonly used as a field-based screening tool.

What are the common causes of wasting?

Common causes include insufficient intake of nutritious foods, infections (like diarrhea, measles), inadequate maternal nutrition, and poor infant feeding practices. These factors often interact and are exacerbated by poverty, conflict, and climate change.

Can wasting be treated effectively?

Yes, wasting is treatable. Uncomplicated severe wasting can be treated with ready-to-use therapeutic food (RUTF) in a community setting. Cases with complications require immediate medical stabilization and specialized feeding in a hospital setting.

What is bilateral pitting edema?

Bilateral pitting edema is a swelling, usually beginning in the feet, that is a key indicator of severe acute malnutrition (SAM). It is called 'pitting' because when pressure is applied, an indentation remains for several seconds.

What are the long-term consequences for children who experience wasting?

Besides the immediate risk of mortality, wasting can weaken the immune system and impair both physical and cognitive development. It also increases the risk of later stunting, leading to long-term health and developmental impairments.

How can child wasting be prevented?

Prevention involves a multi-pronged approach, including ensuring adequate maternal nutrition, promoting exclusive and continued breastfeeding, improving sanitation and hygiene, providing access to nutritious complementary foods, and strengthening health systems.

Why is early detection of wasting so important?

Early detection is critical because the risk of death for a severely wasted child is significantly higher. Identifying wasting early allows for prompt nutritional and medical intervention, which increases the chances of recovery and survival.