Increases in Children Who Have a Healthy Body Mass Index (BMI)

Definition

According to the American Heart Association, a body mass index (BMI) is an indicator of body fatness and is calculated using weight and height measurements. Children are considered to have a healthy weight when their BMI is between the fifth and 85th percentiles for their sex and age. In children, overweight is defined as having a BMI at or above the sex- and age-specific 85th percentile. Obesity is defined being above the 95th percentile. Underweight is defined as having a BMI at or below the sex- and age-specific 5th percentile.

— Excerpted from the Child Trends DataBank

BMI is calculated by taking the child’s weight (in pounds) divided by height squared (in inches), all multiplied by 703. For example, an adult who is six feet, two inches tall and weighs 200 pounds has a BMI of 25.7, which standard weight tables list as overweight. Current BMI age-for-growth charts for the United States are available here.

This indicator, measured at the child level, can be calculated as the number of infants and toddlers (ages zero to three years), who have a healthy BMI (i.e., between the fifth and 85th percentile for their sex and age) divided by the total number of infants and toddlers in a state/community.

The CDC Growth Charts, which refer to nationally representative samples of children between 1963 and 1994, provide data on males and females between the ages of two and 20 years. They are not intended to represent ideal development.1

According to 2011–2012 data from the CDC’s National Health and Nutrition Examination Survey (NHANES), 22.8% of children ages two to five are overweight and 8.4% of children in this age range are obese. Boys in this age group are slightly more likely to be overweight than girls in this age group (23.9% and 21.7%, respectively) and obese (9.5% and 7.2%, respectively).

Additionally, Hispanic children in this age group are more likely to be overweight or obese than their non-Hispanic peers—approximately 29.8% of Hispanic children in this age group are overweight and approximately 16.6% are obese. Asian, non-Hispanic children in this age group are less likely to be overweight and obese than their peers, with approximately 9% overweight and approximately 3.3% obese.2

  • 1. For more information, see Kuczmarski R. J., Ogden C. L., Guo S.S., et al. (2002). 2000 CDC growth charts for the United States: Methods and development. National Center for Health Statistics. Vital Health Stat 11(246).
  • 2. https://www.childtrends.org/indicators/overweight-children-and-youth

Population and sub-population estimates are not available at the community level. However, an individual community may be collecting data for this indicator through a specific program or organization for sub-populations. Additionally, local pediatricians’ offices and health care centers should have these data. It is recommended that a community first evaluate how the data are being collected, where, and for whom (i.e., which sub-populations), and work with those organizations to obtain aggregate, community-level data for children ages zero to three years. Alternatively, if these data are only being collected with certain sub-populations within the community, the community should look to see how the data collection efforts might be able to be expanded to the larger community population.

Research Rationale

Children who are overweight or obese are at increased risk for health and socio-emotional problems, and overweight in the preschool years is highly predictive of being overweight later in childhood. Overweight children are more likely than their peers to develop cardiovascular disease, Type 2 diabetes, liver disease, sleep apnea, high cholesterol, and asthma. There is increasing evidence that the problem of overweight in our population may begin in the earliest years of life.

— Excerpted from “The Youngest Americans: A Statistical Portrait of Infants and Toddlers in the United States”1

  • 1. Murphey, D., Cooper, M., & Forry, N. (2013) The youngest Americans: A statistical portrait of infants and toddlers in the United States. Bethesda, MD: Child Trends. https://www.childtrends.org/wp-content/uploads/2013/11/MCCORMICK-FINAL.pdf