What is childhood obesity?

Childhood obesity is defined by the Centers for Disease Control and Prevention (CDC) as a body mass index (BMI) for children ages 2 to 18 at or above the 95th percentile of children of the same age and sex. BMI is calculated using a child's height and weight. The CDC website has a BMI calculator that you may use to determine your child's BMI. Of note, children at or above the 85th percentile but below the 95th percentile are considered to be overweight.

Currently, approximately 17% of American children and adolescents are considered obese. Body mass index (BMI) is a measure of a person's weight in relationship to his/her height and is used to determine if a child is overweight or obesity.

According to the Centers for Disease Control and Prevention (CDC), children and adolescents (aged 2—19 years) is classified as:

  • Overweight: If his/her BMI is at or above the 85th percentile and lower than the 95th percentile for children of the same age and sex.
  • Obese: If his/her BMI is at or above the 95th percentile for children of the same age and sex.


Diana K. Blythe, MD

Childhood obesity is defined as having a body mass index, or BMI, that is greater than the 95th percentile. Overweight is when the BMI is greater than the 85th percentile.

Even if your child is not yet obese, please talk to your pediatrician about ways to have a better match between height and weight.  If it goes untreated, obesity will affect both your child's physical and mental health.

Teneisha C. Davis, MD
Family Medicine

BMI also known as body mass index is an accepted method of determing if a child is overweight or obese.  This measurement is only accurated in children two and up.

Underweight — BMI <5th percentile for age and sex.

Normal weight — BMI between the 5th and 85th percentile for age and sex.

Overweight — BMI between the 85th and 95th percentile for age and sex.

Obese — BMI ≥95th percentile for age and sex.

Extreme obesity — BMI ≥120 percent of the 95th percentile values, OR a BMI≥35. This corresponds to approximately the 99th percentile, or BMI z-score ≥2.33

Charles J. Sophy, MD
Adolescent Medicine

Childhood obesity is a very serious medical condition that can affect children and adolescents. It is diagnosed when a child is well above the normal weight for his or her age and height.

Childhood obesity is a medical condition in which excess body fat negatively impacts a child’s health and wellbeing. Childhood obesity occurs because of an imbalance between calories consumed and calories a child uses to support normal growth and development, metabolism, and physical activity. Factors that influence childhood obesity include lack physical activity, nutritional habits, genetic factors, and lifestyle factors. There are long-term and short-term health consequences associated with the occurrence of childhood obesity. Long-term and short-term health consequences include Type 2 diabetes, high cholesterol, high blood pressure, heart disease, cancer, sleep apnea, asthma, psychological disorders, social disorders, and emotional disorders. Childhood obesity has become a serious health concern for children and adolescents. Preventing childhood obesity has become an important public health concern because of its high prevalence in the youth population.

Childhood obesity has risen dramatically in the past several decades. A serious medical condition, childhood obesity is particularly troubling because the additional weight can lead to health problems that were once confined to adults, such as diabetes, high blood pressure and high cholesterol."Extremely obese teenagers have obesity-related health problems, particularly diabetes and increased cardiovascular risk," says Ilene Fennoy, MD, Medical Director of the Center for Adolescent Bariatric Surgery and a pediatric endocrinologist at NewYork-Presbyterian Morgan Stanley Children's Hospital.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.