Nutrition Landscape Information System (NLiS)

Help Topic: Malnutrition in children

Underweight, stunting, wasting and overweight

 

What do these indicators tell us?

These indicators are used to measure nutritional imbalance resulting in undernutrition (assessed from underweight, wasting and stunting) and overweight. Child growth is internationally recognized as an important indicator of nutritional status and health in populations.

The percentage of children with a low height for age (stunting) reflects the cumulative effects of undernutrition and infections since and even before birth. This measure can therefore be interpreted as an indication of poor environmental conditions or long-term restriction of a child's growth potential. The percentage of children who have low weight for age (underweight) can reflect 'wasting' (i.e. low weight for height), indicating acute weight loss, 'stunting', or both. Thus, 'underweight' is a composite indicator and may therefore be difficult to interpret.

Stunting, wasting and overweight in children under five years of age are included as primary outcome indicators in the core set of indicators for the Global Nutrition Monitoring Framework to monitor progress towards reaching Global Nutrition Targets 1, 4 and 6. These three indicators are also included in the WHO Global Reference List of 100 Core Health Indicators.

 

How are they defined?

·   Underweight: weight for age < -2 standard deviations (SD) of the WHO Child Growth Standards median

·   Stunting: height for age < -2 SD of the WHO Child Growth Standards median

·   Wasting: weight for height < -2 SD of the WHO Child Growth Standards median

·   Overweight: weight for height > +2 SD of the WHO Child Growth Standards median

 

What are the consequences and implications?

Underweight: As weight is easy to measure, this is the indicator for which most data have been collected in the past. Evidence has shown that the mortality risk of children who are even mildly underweight is increased, and severely underweight children are at even greater risk.

Stunting: Children who suffer from growth retardation as a result of poor diets or recurrent infections tend to be at greater risk for illness and death. Stunting is the result of long-term nutritional deprivation and often results in delayed mental development, poor school performance and reduced intellectual capacity. This in turn affects economic productivity at national level. Women of short stature are at greater risk for obstetric complications because of a smaller pelvis. Small women are at greater risk of delivering an infant with low birth weight, contributing to the intergenerational cycle of malnutrition, as infants of low birth weight or retarded intrauterine growth tend be smaller as adults.

Wasting: Wasting in children is a symptom of acute undernutrition, usually as a consequence of insufficient food intake or a high incidence of infectious diseases, especially diarrhoea. Wasting in turn impairs the functioning of the immune system and can lead to increased severity and duration of and susceptibility to infectious diseases and an increased risk for death.

Overweight: Childhood obesity is associated with a higher probability of obesity in adulthood, which can lead to a variety of disabilities and diseases, such as diabetes and cardiovascular diseases. The risks for most noncommunicable diseases resulting from obesity depend partly on the age at onset and the duration of obesity. Obese children and adolescents are likely to suffer from both short-term and long-term health consequences, the most significant being:

·   cardiovascular diseases, mainly heart disease and stroke;

·   diabetes;

·   musculoskeletal disorders, especially osteoarthritis; and

·   cancers of the endometrium, breast and colon.

 

Cut-off values for public health significance

Indicator

Prevalence cut-off values for public health significance

 

Underweight

< 10%:   Low prevalence

10-19%: Medium prevalence

20-29%: High prevalence

 30%:   Very high prevalence

 

Stunting

< 20%:   Low prevalence

20-29%: Medium prevalence

30-39%: High prevalence

 40%:   Very high prevalence

 

Wasting

< 5%:     Acceptable

5-9%:     Poor

10-14%: Serious

 15%:   Critical

 

Reference: WHO, 1995.

 

Applying similar methodology used to calculate the cut-off values for public health significance for underweight, stunting and wasting, levels of public health significance for overweight (> +2 SD weight-for-height) for children under 5 years of age based on the WHO child growth standards have also been calculated using the data from the WHO Global Database on Child Growth and Malnutrition. However, they are not yet included here as they are currently being evaluated.

 

Source of data

WHO. WHO Global Database on Child Growth and Malnutrition. Department of Nutrition for Health and Development (NHD), Geneva, Switzerlandhttp://www.who.int/nutgrowthdb/en/.

 

Further reading

WHO. Child Growth Standards, publications and peer-reviewed articles. http://www.who.int/childgrowth/publications/en/.

WHO. Physical status: the use and interpretation of anthropometry. Report of a WHO Expert Committee. Technical Report Series No. 854. Geneva, World Health Organization, 1995. http://whqlibdoc.who.int/trs/WHO_TRS_854.pdf.

UNICEF-WHO-The World Bank. Joint child malnutrition estimates - Levels and trends. http://www.who.int/nutgrowthdb/estimates/en/

WHO. Global Targets 2025 to improve maternal, infant and young child nutrition. http://who.int/nutrition/global-target-2025/en/

WHO. Global Nutrition Targets 2025: Stunting policy brief. Geneva, World Health Organization, 2014. http://who.int/nutrition/publications/globaltargets2025_policybrief_stunting/en/

WHO. Global Reference List of 100 Core Health Indicators. Geneva: World Health Organization, 2015. http://www.who.int/healthinfo/indicators/2015/en/

WHO. E-Library of Evidence for Nutrition Actions (eLENA). Interventions by global target. http://www.who.int/elena/global-targets/en

Target 1: 40% reduction in the number of children under-5 who are stunted. http://www.who.int/elena/global-targets/en/#stunting

Target 4: No increase in childhood overweight. http://www.who.int/elena/global-targets/en/#childhoodoverweight  

Target 6: Reduce and maintain childhood wasting to less than 5%. http://www.who.int/elena/global-targets/en/#wasting