Review Growth Velocities including BMI-Child

Summary of Recommendation and Evidence

Population	Recommendation	Grade (What's This?)
Screening of both Genders	This screening is recommended for children.	B

Overview

Growth velocity, or the speed at which something or someone is growing, is often tracked for children. Growth can be measured in length, such as the length of the body or even of one limb, or in overall weight. The velocity aspect of the measurement refers to the change over time. So calculating growth velocity is a simple matter of measuring a child's weight or height at two points in time and then dividing the change by the amount of time.

Normal Growth Velocity of Childhood

Growth Velocity is the rate of growth over a fixed time interval. It helps in determining if child's growth pattern is following the expected normal growth curve. The growth velocity that oscillates close to 50th percentile on growth chart is considered to be normal.

As shown in the graph above, velocity of growth is high during the first two years of life. Deceleration in child growth ends with onset of growth spurt of puberty.

On a growth chart, a measurement that falls "outside the normal range"; arbitrarily defined as 2 or 3 standard deviations on either side of the mean is atypical, but not necessarily indicative of illness.

The abnormal velocities are one with less than 3rd percentile which indicates "slow growth", and the other with more than 95th percentile which indicates "rapid growth"

BMI (Body Mass Index)

Body Mass Index (BMI) is a person’s weight in kilograms divided by the square of height in meters. For children and teens, BMI is age- and sex-specific and is often referred to as BMI-for-age. In children, a high amount of body fat can lead to weight-related diseases and other health issues and being underweight can also put one at risk for health issues.

What is a BMI percentile and how is it interpreted?

After BMI is calculated for children and teens, it is expressed as a percentile which can be obtained from either a graph or a percentile calculator. Because weight and height change during growth and development, as does their relation to body fatness, a child’s BMI must be interpreted relative to other children of the same sex and age.

How is BMI used with children and teens?

For children and teens, BMI is not a diagnostic tool and is used to screen for potential weight and health-related issues. For example, a child may have a high BMI for their age and sex, but to determine if excess fat is a problem, a health care provider would need to perform further assessments. These assessments might include skinfold thickness measurements, evaluations of diet, physical activity, family history, and other appropriate health screenings. The American Academy of Pediatrics recommends the use of BMI to screen for overweight and obesity in children beginning at 2 years old. For children under the age of 2 years old, consult the WHO standards.