In adults, being overweight or obese is based on BMI.

  • Overweight is defined as a body mass index (BMI) greater than or equal to 25.
  • Obesity is defined as having a BMI greater than or equal to 30.
  • Severe or morbid obesity is defined as having a BMI greater than or equal to 40.

In children, being overweight or obese is based on BMI being above normal ranges on growth charts.

  • Overweight is BMI greater than or equal to 85th percentile for gender and age.
  • Obesity is BMI greater than or equal to 95th percentile for gender and age.
  • Severe obesity is BMI greater than or equal to 99th percentile for gender and age.

Being overweight or obese occurs when the amount of calories you take in is consistently greater than the number of calories you use during activity and basic bodily functions.

Being obese can increase your risk of early death and shorten life expectancy.

Other complications of untreated obesity include:

Being overweight can also affect pregnancy and your child.

  • Effects on children may include increased risk of:
    • Diabetes
    • Obesity
    • Congenital anomalies, especially neural tube defects
    • Autism or other neurodevelopmental disorders

You may also experience problems during labor and deliver and having a baby with a high birth weight.