Defining Overweight and Obesity

A person whose weight is higher than what is considered as a normal weight adjusted for height is described as being overweight or having obesity.1

Fast Facts

According to data from the National Health and Nutrition Examination Survey (NHANES), 2013–20142,3,4,5

  • More than 1 in 3 adults were considered to be overweight.
  • More than 2 in 3 adults were considered to be overweight or have obesity.
  • More than 1 in 3 adults were considered to have obesity.
  • About 1 in 13 adults were considered to have extreme obesity.
  • About 1 in 6 children and adolescents ages 2 to 19 were considered to have obesity.

Using Body Mass Index (BMI) to Estimate Overweight and Obesity

BMI is the tool most commonly used to estimate and screen for overweight and obesity in adults and children. BMI is defined as weight in kilograms divided by height in meters squared. For most people, BMI is related to the amount of fat in their bodies, which can raise the risk of many health problems. A healthcare professional can determine if a person’s health may be at risk because of his or her weight.

The tables below show BMI ranges for overweight and obesity.

Adults

BMI of Adults Ages 20 and Older
BMI Classification
18.5 to 24.9 Normal weight
25 to 29.9 Overweight
30+ Obesity (including extreme obesity)
40+ Extreme obesity

An online tool for gauging the BMIs of adults can be found at: https://www.cdc.gov 

Children and Adolescents

BMI of Children and Adolescents Ages 2 to 19
BMI Classification
At or above the 85th percentile on the CDC growth charts Overweight or obesity
At or above the 95th percentile on the CDC growth charts Obesity (including extreme obesity)
At or above 120 percent of the 95th percentile on the CDC growth charts Extreme obesity

Children grow at different rates at different times, so it is not always easy to tell if a child is overweight. The CDC BMI growth charts are used to compare a child’s BMI with other children of the same sex and age. It is important that a child’s health care provider evaluates a child’s BMI, growth, and potential health risks due to excess body weight. An online tool for gauging the BMIs of children and teens can be found at: https://nccd.cdc.gov/dnpabmi/Calculator.aspx 

Causes and Health Consequences of Overweight and Obesity

Factors that may contribute to weight gain among adults and youth include genes, eating habits, physical inactivity, TV, computer, phone, and other screen time, sleep habits, medical conditions or medications, and where and how people live, including their access to healthy foods and safe places to be active.1,6

Overweight and obesity are risk factors for many health problems such as type 2 diabetes, high blood pressure, joint problems, and gallstones, among other conditions.1,6,7

For more information on the causes and health consequences of overweight and obesity, please visit NIDDK’’s webpages on Understanding Adult Overweight and Obesity.

Prevalence of Overweight and Obesity

The data presented on prevalence are from the 2013–2014 NHANES survey of the National Center for Health Statistics (NCHS) unless noted otherwise. NCHS is part of the Centers for Disease Control and Prevention (CDC).2,3,4,5

Adults

Estimated (Age-Adjusted) Percentage of US Adults with Overweight and Obesity by Sex,  2013–2014  NHANES Data

All (Men and Women) Men Women
Overweight or Obesity 70.2 73.7 66.9
Overweight 32.5 38.7 26.5
Obesity (including extreme obesity) 37.7 35 40.4
Extreme obesity 7.7 5.5 9.9

As shown in the above table

  • More than 2 in 3 adults (70.2 percent) were considered to be overweight or have obesity
  • About 1 in 3 adults (32.5 percent) were considered to be overweight
  • More than 1 in 3 adults (37.7 percent) were considered to have obesity
  • About 1 in 13 adults (7.7 percent) were considered to have extreme obesity
  • More than 1 in 3 (38.7 percent) of men, and about 1 in 4 (26.5 percent) of women were considered to be overweight
  • Obesity was higher in women (about 40 percent) than men (35 percent)
  • Extreme obesity was higher in women (9.9 percent) than men (5.5 percent)
  • Almost 3 in 4 men (73.7 percent) were considered to be overweight or have obesity; and about 2 in 3 women (66.9) were considered to be overweight or have obesity.
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