Skip to main content
Social Sci LibreTexts

2.5: Worldwide Variation in Human Growth

  • Page ID
    139030
    • Todd LaMarr
    \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Human Growth Variations

    The growth charts from the World Health Organization (WHO) and the Center for Disease Control and Prevention (CDC) are widely used in the U.S. to describe the physical growth of children. For children in the U.S. the CDC recommends that the WHO growth charts be used to monitor growth for all children from birth up to 2 years of age and then to use the CDC charts for children two years of age and older. [1]

    Despite widespread use of the WHO charts, there are many important limitations. First of all, data participants came from single cities in only six countries (Brazil, Ghana, India, Norway, Oman and the USA). Second, the WHO growth charts use the growth of breastfed infants as the norm for growth, which may not represent the feeding experiences of all infants. Third, the WHO notes that any deviations from its standards should be considered as evidence of ‘abnormal growth’ (World Health Organization, 2006). [2]

    One study compared the data from the WHO's Multicentre Growth Reference Study (MGRS) to data from 55 different countries to see if the growth charts from the WHO can accurately be used with children outside of the six countries the WHO studied (Natale & Rajagopalan, 2014). Results showed that many countries had physical growth outside of what the WHO considers standard, especially for head circumference. Figure \(\PageIndex{1}\) shows the mean weight of two year old males across thirty countries compared to the MGRS mean score and within 0.5 standard deviations. While most of the countries fell within 0.5 standard deviations of the MGRS mean, many countries did not, suggesting that WHO’s growth chart for weight may not be the best reference chart for all children.

    Weight at 2 years for males: 30 countries versus Multicentre Growth Reference Study (MGRS). Chart data in figure caption
    Figure \(\PageIndex{1}\): Weight at 2 years: 30 countries versus Multicentre Growth Reference Study (MGRS). The green box delimits the area within 0.5 SD of the MGRS mean. The green line within the box shows the MGRS mean. (A) Boys; MGRS mean: 12.2 kg; SD up: 1.55 kg, down: 1.25 kg. (B) Girls; MGRS mean: 11.5 kg; SD up: 1.65 kg, down: 1.25 kg. Error bars show 1 SE.. [3])

    Figure \(\PageIndex{2}\) shows the mean head circumference of two year old females across twenty-six countries compared to the MGRS mean score and within 0.5 of the standard deviations. Interestingly, head circumference was the growth measurement that varied the most. The majority of the countries fell outside of 0.5 standard deviations of the MGRS mean, suggesting that the WHO’s growth chart for head circumference may only be an accurate reference chart for a select few countries.

    Head circumference at 2 years for females: 26 countries versus Multicentre Growth Reference Study (MGRS). Chart data in figure caption
    Figure \(\PageIndex{2}\): Head circumference at 2 years for females: 26 countries versus Multicentre Growth Reference Study (MGRS). ([4])

    The data from this study suggest that the WHO growth charts may not be appropriate for all children around the world, especially for monitoring the growth of head circumference. The study acknowledges important differences in the physical development of infants and toddlers exist across countries. Growth patterns and reference charts for children from specific countries are becoming more available (Bonthuis et al., 2012; Cole, & Mori, 2018; Zhang et al., 2019). If caregivers monitor the physical growth of children, they should search for charts that best represent the demographics of the children they serve and not assume commonly used reference charts are accurate for all infants and toddlers.

    What is the take away message for infant and toddler caregivers?

    • Physical development is important because when children measure below average growth, they are at risk of long term developmental challenges.
    • Physical growth is commonly measured with birth weight, height/length and head circumference.
    • The percentage of infants and toddlers who are at risk due to lower than average physical growth varies by country, state and racial/ethinic group, among other factors.
    • Knowledge of the regional percentage of infants and toddlers measuring lower than average for birth weight, height/length and head circumference could be important information for caregivers as they prepare to meet the needs of the individual children they serve.
    • Quality caregiving is essential for all children, but is especially important for children who are at a developmental risk, such as children with a LBW, children who have experienced stunting and children with a lower than average head circumference.
    • Caregiving characteristics such as providing sensitive and responsive care as well as practices that increase the quantity and quality of language exposure support the optimal development of all children, especially children who are at long term developmental risk due to lower than average scores on physical development.
    • If caregivers monitor the physical growth of infants and toddlers, they should search for charts that best represent the demographics of the children they serve as commonly used charts from the WHO and the CDC do not accurately represent the physical growth of all children.

    [1]Growth Charts” from the CDC is in the public domain.

    [2] Natale & Rajagopalan (2014). Worldwide variation in human growth and the World Health Organization growth standards: A systematic review. BMJ Open, 4(1), e003735. CC by NC 3.0

    [3] Image adapted from Natale & Rajagopalan (2014). Worldwide variation in human growth and the World Health Organization growth standards: A systematic review. BMJ Open, 4(1), e003735. CC by NC 3.0

    [4] Image adapted from Natale & Rajagopalan (2014). Worldwide variation in human growth and the World Health Organization growth standards: A systematic review. BMJ Open, 4(1), e003735. CC by NC 3.0


    This page titled 2.5: Worldwide Variation in Human Growth is shared under a mixed 4.0 license and was authored, remixed, and/or curated by Todd LaMarr.