Also, this category means that the child has an increased risk of continued obesity into adulthood. This is where we begin to be concerned about children developing health risks because of their weight, such as prediabetes, hypertension or high cholesterol. 95th percentile or higher: This is considered obesity.Unlike adults, where this range is where we start to see an increase in some health risks in children, this range means the child is at an increased risk of crossing over into the obesity category, either in childhood or later in adulthood.

85th to less than the 95th percentile: This is considered overweight.5th to less than the 85th percentile: This is what is considered a healthy weight for most children.Less than the 5th percentile for age and sex: This is considered underweight, which could potentially be worrisome if the child is not receiving adequate nutrition.In general, the percentiles break down to: The calculation of this BMI percentile can be plotted on a growth chart to give a sense of where they fall compared to other children of the same sex and age. So for children, the number on a scale is not the only important factor when it comes to their weight status, but also what their height, age and sex are. This is because of the significant differences in the range of heights and weights that a child of 6 years of age can have. For example, a BMI of 22 in adults falls into the “healthy weight” category, though a BMI of 22 in a 6-year-old child would be in the obesity range. BMI PercentilesĪs kids are constantly growing taller and their bodies are changing, we cannot use the same BMI cut-offs for adults. Nowadays, it’s usually not a paper growth chart that we look at with families, as BMI percentiles are automatically calculated in the electronic health record or an online calculator. Most importantly, the 2000 growth charts included information on BMI. In 1977, new growth charts were introduced based on more representative data and then updated again in 2000. The most widely used growth charts from the 1940s to the 1970s were based on measurements of white children in Iowa and Boston. So like all things pediatric, we use the growth chart! Growth charts have been in use since the early 1900s, but previous versions had plenty of problems – they didn’t include preschool-aged children and didn’t represent all children in the U.S., particularly those from traditionally underrepresented backgrounds and different areas of the country. It’s the same calculation for children and adults – weight in kilograms divided by height in meters squared:įor children, we don’t look at raw BMI (a number usually between 18-40) but instead, we look at BMI percentiles, taking into account the child’s sex and age. Similar to adults, we do use body mass index, or BMI, to take height and weight into account together. Talking about a child’s growth, height and weight involves nuance and is more complicated than evaluating an adult’s weight status. Most children should gain weight as they get older – they are growing muscles and bones, which weigh a lot! So it is nearly impossible to tell a parent what their child “should” weigh. Throughout childhood and adolescence, their level of adiposity, or how much fat-to-lean mass they have, changes as they get older. Children are constantly growing and changing, and they go through growth spurts at different times. Learn about Childhood/Adolescent Obesityīy Joseph Skelton, MD, MS and Callie Brown, MD, MPHĪs pediatricians, we frequently get asked by parents, “what should my child weigh?” A common saying in pediatrics is that “kids are not little adults,” and this is particularly important when considering a child’s weight.

Bmi children percentile calculation