What is Obesity?
[[File:La monstrua desnuda (1680), de Juan Carreño de Miranda..jpg|thumb|A 1680 painted by [[Juan Carreno de Miranda]] of a girl presumed to have [[Prader–Willi syndrome]]<ref>{{cite web|url=http://www.esst.org/newsletter2000.htm |title=Case Study: Cataplexy and SOREMPs Without Excessive Daytime Sleepiness in Prader Willi Syndrome. Is This the Beginning of Narcolepsy in a Five Year Old? |author=Mary Jones |publisher=European Society of Sleep Technologists |accessdate=April 6, 2009}}</ref>]] [[File:Belly of an obese teenage boy.jpg|thumb|An obese teenage boy]] [[File:Bmi30chart.png|thumb|right|Percentage of the adult population with a BMI over 30, for the [[OECD]] countries]] '''Obesity''' is the condition of being much too heavy for one's height so that one's health is affected. In other words, it means to be too [[overweight]]. Also known as being fat. It is considered a [[disease]] and has been described as an [[epidemic]] and a form of [[suicide]]. To know if a person is overweight, the [[body mass index]] (BMI) is calculated, by dividing the person's weight (in kilograms), by their height (in metres) squared (multiplied by itself). (This is only meaningful for [[adult]]s who are fully grown, and should not be used for [[child]]ren. Growth charts can be used to measure obesity in children.) A BMI between 18.5 and 25 is considered ''normal''. People with a BMI of 25 or more are said to be overweight; with 30 and above, they are considered obese, and with 35 and above, they are considered ''severely obese'' (this used to be called ''morbidly obese''). In general, the BMI number is a good quantifiable measurement of a person's obesity. However, it is a poor predictor in people who are very athletic, because a person with a higher than average amount of muscle tissue will weigh more than an average person, thus resulting in a BMI that is higher than normal, even if that person is very large. In 2024 a study of more than 220 million people in almost 200 countries, found that more than 1 billion people were obese