Overweight and obesity

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. The rise in overweight and obesity is a major public health concern, threatening progress in tackling cardiovascular diseases.

A number of behavioural and environmental factors have contributed to the long-term rise in overweight and obesity rates in OECD countries, including the widespread availability of energy dense foods and more time spent being physically inactive. These factors have created obesogenic environments, putting people, and especially those socially vulnerable, more at risk of obesity.


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 from 25 to 30 are defined as overweight, and those with a BMI of 30 or over as obese.


The BMI classification may not be suitable for all ethnic groups, who may have equivalent levels of risk at lower or higher BMI. The thresholds for adults are also not suitable to measure overweight and obesity among children.

For half of the countries, overweight and obesity rates are self-reported through estimates of height and weight from population-based health interview surveys. However, the other half of OECD countries derives their estimates from health examinations. These differences limit data comparability. Estimates from health examinations are generally higher, and more reliable than estimates from health interviews. The OECD average is based on both types of estimates (self-reported and measured) and, thus, may be underestimated.


Based on the latest available surveys, more than half (53.8%) of the adult population in OECD countries report that they are overweight or obese. In countries where height and weight were measured (as opposed to self-reported), this proportion is even greater, at 57.5%. The prevalence of overweight and obesity among adults exceeds 50% in no less than 22 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 have been increasing.

The prevalence of obesity, which presents even greater health risks than overweight, varies about six fold across OECD countries, from a low of less than 5% in Japan and Korea, to over 32% in Mexico and the United States. Across OECD countries, 19% of the adult population is obese. Obesity rates in men and women are similar in most countries. However, in Chile, Mexico and Turkey, as well as Russia and South Africa, a greater proportion of women are obese, while the reverse is true in Slovenia.

The prevalence of obesity has increased over the past decade in all OECD countries. In 2013, at least one in five adults was obese in twelve OECD countries, compared to one in eight a decade ago. Since 2000, obesity rates have increased by a third or more in 14 countries. The rapid rise occurred regardless of where levels stood a decade ago. Obesity increased by around 45% in both Denmark and Australia, even though the current rate in Denmark is less than half that of Australia.

The rise in obesity has affected all population groups, regardless of sex, age, race, income or education level, but to varying degrees. Evidence from Canada, the United Kingdom, France, Italy, Mexico, Spain, Switzerland and the United States shows that obesity tends to be more common in lower educated groups, especially in women.


Further information

Analytical publications

Statistical publications


Obesity rates among the adult population
Percentage of population aged 15 and over, 2013 or latest available year


Increasing obesity rates among the adult population
Percentage of population aged 15 and over, 2000-13 or latest available period