OECD Factbook 2013: Economic, Environmental and Social Statistics
branch Health
branch Risk factors
    branch Overweight and obesity

The rise in overweight and obesity is a major public health concern. Obesity is a known risk factor for numerous health problems, including hypertension, high cholesterol, diabetes, cardiovascular diseases, respiratory problems (asthma), musculoskeletal diseases (arthritis) and some forms of cancer. A number of behavioural and environmental factors have contributed to the rise in overweight and obesity rates in industrialised countries, including falling real prices of food and more time being physically inactive.

Because obesity is associated with higher risks of chronic illnesses, it is linked to significant additional health care costs. There is a time lag between the onset of obesity and related health problems, suggesting that the rise in obesity over the past two decades will mean higher health care costs in the future. Mortality also increases sharply once the overweight threshold is crossed.


Overweight and obesity are defined as excessive weight presenting health risks because of the high proportion of body fat. The most frequently used measure is based on the body mass index (BMI), which is a single number that evaluates an individual's weight in relation to height (weight/height2, with weight in kilograms and height in metres). Based on the WHO classification, adults with a BMI between 25 and 30 are defined as overweight, and those with a BMI over 30 as obese.


The BMI classification may not be suitable for all ethnic groups, who may be exposed to different levels of health risk for the same level of BMI. The thresholds for adults are also not suitable to measure overweight and obesity among children.

For most countries, overweight and obesity rates are self-reported through estimates of height and weight from population-based health interview surveys. However, around one-third of OECD countries derive their estimates from health examinations. These differences limit data comparability. Estimates from health examinations are generally higher and more reliable than from health interviews.

The following countries use measured data: Australia, Canada, Chile, the Czech Republic, Finland, Hungary, Ireland, Japan, Korea, Luxembourg, Mexico, New Zealand, the Slovak Republic, the United Kingdom and the United States.


Based on latest available surveys, more than half (53%) of the adult population in the OECD report that they are overweight or obese. Among those countries where height and weight were measured, the proportion was even greater, at 57%. The prevalence of overweight and obesity among adults exceeds 50% in no less than 21 of 34 OECD countries. In contrast, overweight and obesity rates are much lower in Japan and Korea and in some European countries (France and Switzerland), although even in these countries rates are increasing.

The prevalence of obesity, which presents even greater health risks than overweight, varies almost tenfold among OECD countries, from a low of 4% in Japan and Korea, to 30% or more in the United States and Mexico. On average across OECD countries, 18% of the adult population are obese. Average obesity rates among men and women are similar, although there are disparities in some countries. In Chile, Turkey and Mexico, a greater proportion of women are obese, whereas in Iceland and Norway men are more likely to be obese.

Obesity prevalence has increased by more than 40% over the past 10 years in a number of countries, including Denmark, Sweden, Norway, France and the Czech Republic, with the OECD average rising from 13% in 2000 to 18% in 2010. The rapid rises occurred regardless of where levels stood a decade ago, with the prevalence of obesity increasing by half in both Norway and the Czech Republic, even though the current rate in Norway is around half that of the Czech Republic.



Further information
Analytical publications
Statistical publications
Online databases
Indicator in PDF Acrobat PDF page

Overweight and obesity population aged 15 and above
    Table in Excel

Increasing obesity rates among the adult population Figure in Excel
Increasing obesity rates among the adult

Visit the OECD web site