Obesity

Extra facts

• Of the 1.4 billion overweight adults (defined as 20 and older) recorded in 2008, over 200 million men and nearly 300 million women were obese.
• 65 percent of the world's population lives in countries where overweight and obesity kills more people than do factors related to underweight.
• More than 40 million children under the age of five were overweight in 2010. Once considered a high-income country problem, overweight and obesity are now on the rise in low- and middle-income countries, particularly in urban settings.
• At least 2.8 million adults die each year as a result of being overweight or obese. In addition, 44 percent of the diabetes burden, 23 percent of the ischemic heart disease burden and between 7 and 41 percent of certain cancer burdens are attributable to being overweight and obese.
• Many low- and middle-income countries are now facing a "double burden" of disease. While they continue to deal with the problems of infectious disease and undernutrition, they are experiencing a rapid upsurge in noncommunicable disease risk factors such as being overweight and obese, particularly in urban settings.
• It is not uncommon to find undernutrition and obesity existing side-by-side in the same country, the same community or the same household.

WHO, 2012

Methods, caveats and issues

Overweight and obesity are defined as abnormal or excessive fat accumulation that may impair health.

Body mass index (BMI) is a simple index of weight-for-height that is commonly used to classify overweight and obesity in adults. It is defined as a person's weight in kilograms divided by the square of his height in meters (kg/m²). The WHO definition is:

• A BMI greater than or equal to 25 is overweight.
• A BMI greater than or equal to 30 is obesity.

WHO, 2012

Sources

[WHO] World Health Organization. 2012. Obesity and overweight. Fact sheet n°311. Geneva: WHO. (Available from http://www.who.int/mediacentre/factsheets/fs311/en/)