What is Global Acute Malnutrition (GAM)?

December 5, 2025 •

3 min read

According to UNICEF and the World Health Organization (WHO), 45 million children under the age of 5 suffered from acute malnutrition in 2022, a condition often assessed using a metric known as Global Acute Malnutrition (GAM). This statistic underscores the urgency and scale of the issue. Global acute malnutrition refers to a population-level measurement used to assess the nutritional status of a specific group, typically children aged 6 to 59 months, within the context of a humanitarian emergency or food crisis.

Quick Summary

This article defines Global Acute Malnutrition (GAM), details its measurement, explores the underlying causes, discusses its health consequences, and outlines treatment and prevention strategies, distinguishing it from related nutritional issues.

Key Points

GAM is a Population-Level Indicator: Global Acute Malnutrition (GAM) measures acute malnutrition in a population, often children aged 6 to 59 months.
MAM and SAM are its Components: GAM includes Moderate Acute Malnutrition (MAM) and Severe Acute Malnutrition (SAM). For definitions, see {Link: NCBI Books https://www.ncbi.nlm.nih.gov/books/NBK361900/}.
Food Insecurity and Disease are Key Causes: Drivers of GAM include insufficient food access and a cycle of infection and malnutrition, worsened by poor sanitation.
Diagnosis Relies on Anthropometry and Clinical Signs: Diagnosis uses MUAC tapes and checking for bilateral pitting edema.
Treatment Involves Community and Inpatient Care: CMAM treats most cases with RUTFs; complicated cases need inpatient care.
Prevention Focuses on Holistic Interventions: Prevention includes promoting breastfeeding, improving WASH, disease treatment, and addressing socioeconomic factors.
High GAM Signals a Critical Emergency: High GAM rates, particularly above 15%, indicate a critical emergency requiring immediate action.

Global Acute Malnutrition (GAM) represents the combined prevalence of Moderate Acute Malnutrition (MAM) and Severe Acute Malnutrition (SAM) within a population. Unlike assessing an individual's nutritional status, GAM provides a crucial snapshot of the overall public health situation in a specific region, making it an indispensable tool for humanitarian and health organizations. A high GAM rate often signals a severe emergency requiring immediate intervention.

Defining the Components: MAM and SAM

Global Acute Malnutrition is comprised of Moderate Acute Malnutrition (MAM) and Severe Acute Malnutrition (SAM). The World Health Organization (WHO) defines these based on anthropometric measurements. For a detailed breakdown of these definitions, refer to {Link: NCBI Books https://www.ncbi.nlm.nih.gov/books/NBK361900/}. SAM is the most serious form and carries a significantly higher risk of death.

Wasting, a loss of muscle and fat, and edema, swelling due to fluid retention (historically called kwashiorkor), are different presentations of acute malnutrition.

Causes and Risk Factors

GAM arises from a combination of immediate and underlying factors, often illustrated by the UNICEF framework. Key causes include:

Food Insecurity: Insufficient food due to crises like droughts, conflicts, or economic shocks. High GAM is a sign of widespread food insecurity.
Infections and Disease: Malnutrition weakens the immune system, increasing susceptibility to infections, which in turn worsen malnutrition. Poor water and sanitation contribute to this cycle.
Inadequate Care Practices: Suboptimal infant feeding practices, including lack of exclusive breastfeeding.
Socioeconomic and Environmental Factors: Poverty, low education levels, and unstable conditions exacerbate the risk. Climate change and displacement also play a role.

Health Consequences and Diagnosis

The consequences of acute malnutrition are severe, especially for young children, leading to developmental issues, increased illness, and death. Diagnosis uses several methods:

Anthropometric Measurements: Weight-for-height and MUAC measurements are key for children 6-59 months. MUAC is useful for community screening. The primary indicators are Weight-for-Height Z-score (WHZ) and Mid-Upper Arm Circumference (MUAC).
Clinical Signs: Checking for bilateral pitting edema.
Medical Complications: Assessing for issues like low blood sugar or dehydration requiring hospital care.

GAM vs. SAM vs. Wasting: A Comparison


Feature	Global Acute Malnutrition (GAM)	Severe Acute Malnutrition (SAM)	Wasting (Acute Malnutrition)
Measurement Level	Population-level statistic	Individual-level diagnosis	Individual-level diagnosis
Inclusion	Includes both Moderate Acute Malnutrition (MAM) and SAM cases	A sub-category of acute malnutrition; extremely low WHZ/MUAC	A general term for low weight-for-height or MUAC
Significance	Indicator of humanitarian crisis severity	Indicates very high risk of mortality	Short-term nutritional deterioration
Diagnostic Criteria	Based on population surveys using WHZ and MUAC thresholds	WHZ < -3 SD, MUAC < 115mm, or edema	WHZ < -2 SD or MUAC < 125mm (includes MAM and SAM)

Prevention and Treatment Strategies

Addressing GAM requires a multi-faceted approach. Treatment strategies for individuals include:

Community Management of Acute Malnutrition (CMAM): Treating uncomplicated SAM and MAM in communities using Ready-to-Use Therapeutic Foods (RUTFs) and Supplementary Foods (RUSFs).
Inpatient Care: Hospitalization for children with complicated SAM.
Exclusive Breastfeeding: A vital preventive measure for the first six months.
Disease Prevention: Integrating nutrition with water, sanitation, and hygiene (WASH) programs.
Micronutrient Supplementation: Providing essential vitamins and minerals.

Conclusion

Global acute malnutrition is a critical public health indicator reflecting a population's nutritional status. High GAM rates signal a severe crisis, indicating widespread food insecurity and vulnerability. Effective intervention requires coordinated efforts beyond just food aid, focusing on strengthening healthcare, preventive strategies like better feeding practices and sanitation, and targeted treatments. Addressing underlying political, economic, and environmental factors is key to long-term progress.

Frequently Asked Questions

GAM is a population-level measurement that includes all cases of acute malnutrition, both moderate and severe. SAM, on the other hand, is a specific diagnosis for the most severe form of acute malnutrition in an individual child, based on very low weight-for-height, low MUAC, or edema.

GAM is typically measured through population surveys that collect anthropometric data from children aged 6 to 59 months. The primary indicators are Weight-for-Height Z-score (WHZ) and Mid-Upper Arm Circumference (MUAC).

Common causes include food insecurity due to economic shocks or crises, high rates of infectious diseases (especially diarrhea), inadequate child feeding and care practices, and underlying factors like poverty, poor sanitation, and maternal education levels.

The primary treatment involves providing therapeutic foods. Uncomplicated cases are managed at the community level with Ready-to-Use Therapeutic Foods (RUTFs), while children with medical complications or edema are treated in inpatient facilities.

Early signs in children can include unintentional weight loss or a failure to gain weight at a normal rate, a lack of appetite, irritability, and low energy levels. In severe cases, visible wasting and bilateral pitting edema may appear.

Prevention strategies focus on a holistic approach that includes promoting exclusive breastfeeding, ensuring access to a diverse diet, improving water, sanitation, and hygiene (WASH), and enhancing healthcare services.

Children under five have higher nutritional needs for their rapid growth and development and are more susceptible to infections. This makes them especially vulnerable to the effects of undernutrition, which can have long-lasting impacts on their health and cognitive abilities.