Key facts from World Health Organization
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Worldwide obesity has nearly doubled since 1980.
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In 2008, more than 1.4 billion adults, 20 and older, were overweight. Of these over 200 million men and nearly 300 million women were obese.
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35% of adults aged 20 and over were overweight in 2008, and 11% were obese.
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65% of the world's population live in countries where overweight and obesity kills more people than underweight.
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More than 40 million children under the age of five were overweight in 2011.
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Obesity is preventable.
What are overweight and obesity?
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:
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a BMI greater than or equal to 25 is overweight
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a BMI greater than or equal to 30 is obesity.
BMI provides the most useful population-level measure of overweight and obesity as it is the same for both sexes and for all ages of adults. However, it should be considered a rough guide because it may not correspond to the same degree of fatness in different individuals.
Facts about overweight and obesity
Overweight and obesity are the fifth leading risk for global deaths. At least 2.8 million adults die each year as a result of being overweight or obese. In addition, 44% of the diabetes burden, 23% of the ischemic heart disease burden and between 7% and 41% of certain cancer burdens are attributable to overweight and obesity.
Some WHO global estimates from 2008 follow.
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More than 1.4 billion adults, 20 and older, were overweight.
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Of these overweight adults, over 200 million men and nearly 300 million women were obese.
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Overall, more than 10% of the world’s adult population was obese.
In 2011, more than 40 million children under the age of five were overweight. 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. More than 30 million overweight children are living in developing countries and 10 million in developed countries.
Overweight and obesity are linked to more deaths worldwide than underweight. For example, 65% of the world's population live in countries where overweight and obesity kill more people than underweight (this includes all high-income and most middle-income countries).
What causes obesity and overweight?
The fundamental cause of obesity and overweight is an energy imbalance between calories consumed and calories expended. Globally, there has been:
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an increased intake of energy-dense foods that are high in fat; and
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an increase in physical inactivity due to the increasingly sedentary nature of many forms of work, changing modes of transportation, and increasing urbanization.
Changes in dietary and physical activity patterns are often the result of environmental and societal changes associated with development and lack of supportive policies in sectors such as health, agriculture, transport, urban planning, environment, food processing, distribution, marketing and education.