This publication describes the prevalence of overweight and obesity in the United States.
- Overweight refers to an excess amount of body weight that may come from muscles, bone, fat, and water.
- Obesity refers to an excess amount of body fat.
Using Body Mass Index (BMI) to Estimate Overweight and Obesity
The BMI is the tool most commonly used to estimate overweight and obesity in children and adults.
For adults, overweight and obesity ranges are measured by using weight and height to compute the person's BMI. The BMI is used because, for most people, it correlates with the amount of fat in their bodies.
Children grow at different rates at different times, so it is not always easy to tell if a child is overweight. BMI charts for children compare their height and weight to other children of their same sex and age.
The tables at the bottom outline BMI scores and weight categories for adults and children. Online tools for gauging the BMIs of children and adults are listed in the Resources section of this fact sheet.
Data from the National Health and Nutrition Examination Survey, 2009–2010
- More than 2 in 3 adults are considered to be overweight or obese.
- More than 1 in 3 adults are considered to be obese.
- More than 1 in 20 adults are considered to have extreme obesity.
- About one-third of children and adolescents ages 6 to 19 are considered to be overweight or obese.
- More than 1 in 6 children and adolescents ages 6 to 19 are considered to be obese.
BMI of Adults Age 20 and Older
|18.5 to 24.9||Normal weight|
|25 to 29.9||Overweight|
|40 +||Extreme obesity|
BMI of Children and Adolescents Ages 2–19
|At or above the 85th percentile||Overweight or obese|
|At or above the 95th percentile||Obese|
Health Risks of Overweight and Obesity
- type 2 diabetes
- heart disease
- high blood pressure
- nonalcoholic fatty liver disease (excess fat and inflammation in the liver of people who drink little or no alcohol)
- osteoarthritis (a health problem causing pain, swelling, and stiffness in one or more joints)
- some types of cancer: breast, colon, endometrial (related to the uterine lining), and kidney
Causes of Overweight and Obesity
Overweight and obesity result from an energy imbalance. The body needs a certain amount of energy (calories) from food to keep up basic life functions. Body weight tends to remain the same when the number of calories eaten equals the number of calories the body uses or “burns.” Over time, when people eat and drink more calories than they burn, the energy balance tips toward weight gain, overweight, and obesity.
Children need to balance their energy, too, but they are also growing and that should be considered as well. Energy balance in children happens when the amount of energy taken in from food or drink and the energy being used by the body support natural growth without promoting excess weight gain.
Many factors can lead to energy imbalance and weight gain. They include genes, eating habits, how and where people live, attitudes and emotions, life habits, and income.
Treatment of Overweight and Obesity
Overweight and obesity are risk factors for type 2 diabetes, heart disease, high blood pressure, and other health problems (see box).
There is no single cause of all overweight and obesity. There is no single approach that can help prevent or treat overweight and obesity. Treatment may include a mix of behavioral treatment, diet, exercise, and sometimes weight-loss drugs. In some cases of extreme obesity, weight-loss surgery may be an option.
The Weight-control Information Network (WIN) is a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) of the National Institutes of Health (NIH)
Source: National Institute of Diabetes and Digestive and Kidney Diseases; National Institutes of Health; NIH Publication Number 04–4158
1. National Institutes of Health. Clinical guidelines on the identification, evaluation, and treatment of overweight and obesity in adults: The evidence report. National Heart, Lung, and Blood Institute; September 1998. NIH Publication No. 98–4083. www.nhlbi.nih.gov
2. Flegal KM, Carroll MD, Kit BK, Ogden CL. Prevalence of obesity and trends in the distribution of body mass index among US adults, 1999–2010. Journal of the American Medical Association. 2012; 307(5):491–97. Available online: jama.ama-assn.org
3. Ogden CL, Carroll MD, Kit BK, Flegal KM. Prevalence of obesity and trends in body mass index among US children and adolescents, 1999–2010. Journal of the American Medical Association. 2012; 307(5):483–90. Available online: jama.ama-assn.org
- National Diabetes Education Program www.yourdiabetesinfo.org
- National Diabetes Information Clearinghouse diabetes.niddk.nih.gov
- National Health and Nutrition Examination Survey (NHANES) www.cdc.gov
- National Health Interview Survey (NHIS) www.cdc.gov
- Online BMI Calculators
Children and teens: nccd.cdc.gov/dnpabmi/Calculator.aspx
© Copyright 1995-2016 The Cleveland Clinic Foundation. All rights reserved.
This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 11/12/2012...#5783