Child Nutrition and Growth

Child nutrition and growth concerns how adequate diet and the absence of disease allow children to attain healthy physical and cognitive development, and what happens when they do not. Undernutrition - encompassing stunting, wasting, and micronutrient deficiencies - is an underlying contributor to a large share of child deaths and to lifelong impairment, while overweight is a growing concern, making this a central topic in global child health.

Definition

Child nutrition and growth is the study of children's nutritional status and physical growth relative to reference standards, including undernutrition (stunting, wasting, underweight, and micronutrient deficiencies) and overweight, and their causes and consequences for survival and development.

Scope

This topic covers the main forms and anthropometric measures of child undernutrition (stunting, wasting, underweight), micronutrient deficiencies, the concept of the first 1000 days, the long-term consequences of early growth faltering, and the coexisting rise of childhood overweight. It is reference material on the epidemiology and significance of child nutrition, not dietary or clinical advice.

Core questions

• How are stunting, wasting, and underweight defined and measured against growth standards?
• What share of child mortality and morbidity is attributable to undernutrition?
• Why are the first 1000 days considered a critical window for growth and development?
• How do undernutrition and overweight coexist in low- and middle-income countries?

Key concepts

• Stunting (low height-for-age)
• Wasting (low weight-for-height)
• Underweight (low weight-for-age)
• Micronutrient deficiencies
• The first 1000 days
• Growth standards and z-scores
• Double burden of malnutrition

Mechanisms

Inadequate dietary intake and repeated infection interact to impair growth: poor nutrient supply, recurrent illness such as diarrhoea, and adverse maternal and intrauterine conditions lead to linear growth faltering (stunting) and acute weight loss (wasting). Early undernutrition is associated with increased mortality and infection risk and with longer-term deficits in cognition and capacity, while excess intake and changing diets drive rising overweight in some settings, producing a double burden (Black, 2008; Black, 2013).

Clinical relevance

Knowledge of child nutrition and growth informs how populations are assessed and how nutrition programmes are prioritised. This entry describes population patterns, measures, and consequences and does not provide individual dietary, supplementation, or treatment recommendations.

Epidemiology

Undernutrition is concentrated in low- and middle-income countries and is estimated to underlie a substantial fraction of deaths in children under five through its contribution to infectious disease (Black, 2008). More recent analysis documents persisting high stunting and wasting alongside a rising prevalence of childhood overweight, the so-called double burden of malnutrition (Black, 2013).

Evidence & guidelines

The principal global evidence comes from The Lancet maternal and child nutrition series and from WHO and UNICEF growth standards and joint malnutrition estimates, which define the anthropometric thresholds and quantify global burden used in target-setting.

History

Quantifying the contribution of undernutrition to child death and disease was advanced by successive Lancet nutrition series (2008 and 2013), which moved the field from cataloguing deficiencies toward estimating attributable burden and evaluating intervention packages, and helped frame nutrition targets within global child-health goals.

Debates

How should the double burden of malnutrition be addressed?

As childhood overweight rises while undernutrition persists, there is debate over whether and how programmes can tackle both simultaneously without one set of interventions worsening the other.

Key figures

• Robert E. Black
• Zulfiqar A. Bhutta
• Cesar G. Victora

Seminal works

• black-2008
• black-2013

Frequently asked questions

What is the difference between stunting and wasting?

Stunting is low height-for-age, reflecting chronic or recurrent undernutrition, while wasting is low weight-for-height, reflecting acute or severe recent undernutrition; the two capture different time scales of growth failure.

Why are the first 1000 days emphasised?

The period from conception to a child's second birthday is a critical window when nutrition strongly shapes growth and brain development, and deficits incurred then are difficult to reverse later.