Although childhood obesity gets a lot of attention, some children struggle with the opposite problem: they struggle to gain weight.

So how can parents know if their child is “too skinny”?

Although the best resource is probably a children’s pediatrician, experts have also spoken out on the subject.

“Underlying health conditions can cause children and adolescents to be underweight. Additionally, being underweight may indicate malnutrition,” the U.S. Centers for Disease Control and Prevention noted in a recent report. study on the prevalence of underweight children in the United States.

Just over 4% of children and adolescents ages 2 to 19 were underweight in the United States in 2018, according to the study.

To help you determine if your child is too thin, here’s what you need to know.