Obesity, as defined by the World Health Organisation, is abnormal or excessive fat accumulation that presents a risk to health.
A crude measure of obesity is the body mass index (BMI), a person’s weight (in kilograms) divided by the square of his or her height (in metres). A person with a BMI of 30 or more is generally considered obese.
Obesity is considered a major risk factor for a number of chronic diseases, including diabetes, cardiovascular diseases and cancer.
According to research by the House of Commons Library:
- Currently 27% of adults and 20% of children (aged 10-11) in England have obesity. Prevalence is predicted to increase, alongside the numerous associated physical and mental health conditions, and reduced life expectancy.
- The cost of obesity is highly uncertain but the latest estimate of the annual cost to the NHS in England is £5.1 billion, projected to reach £9.7 billion by 2050. This is only the cost to the health service; the total cost to the economy will be greater.
Key facts about obesity according to the World Health Organisation:
- Worldwide obesity has more than doubled since 1980.
- In 2014, more than 1.9 billion adults, 18 years and older, were overweight. Of these over 600 million had obesity.
- 39% of adults aged 18 years and over were overweight in 2014, and 13% had obesity.
- Most of the world's population live in countries where overweight and obesity kills more people than underweight.
- 41 million children under the age of 5 were overweight or had obesity in 2014.
- Obesity is preventable.
The impartial House of Commons Library has published a 'key issues' briefing on obesity, which is available here.
It has also published a full statistics briefing, available here.