title: Defining morbid obesity in children based on BMI 40 at age 18 using the extended international (IOTF) cut-offs.
abstract: BACKGROUND
  Studies have reported that children who are obese are becoming more severely obese.
  
  
  OBJECTIVE
  We aimed to classify obese children based on age- and gender-specific centile curves passing through body mass index (BMI) 30, 35 and 40 at age 18 as 'class I', 'class II' or severe, and 'class III' or morbid obesity.
  
  
  METHODS
  In addition to the International Obesity Task Force BMI cut-offs corresponding to BMI 30 and 35, we calculated the BMI cut-offs corresponding to BMI 40 using the LMS method proposed by Cole and Lobstein. We classified 217 obese children according to these criteria.
  
  
  RESULTS
  Fifty-six (25.8%) children had class III obesity, 73 (33.6%) class II obesity and 88 (40.6%) class I obesity. Class III obese children had a higher waist circumference, systolic blood pressure and fasting insulinaemia compared with less obese children.
  
  
  CONCLUSIONS
  It is clinically important to classify obese children in different classes of obesity severity.
authors.affiliation: Faculty of Medicine and Life Sciences, Hasselt University, Diepenbeek, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Bervoets
authors.forename: G
authors.initials: G
authors.lastname: Massa
mesh_terms: D000293:Adolescent; D001794:Blood Pressure; D001823:Body Composition; D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D009767:Obesity, Morbid / Q000145:classification* / Q000175:diagnosis* / Q000453:epidemiology; D015995:Prevalence; D012016:Reference Values; D012307:Risk Factors; D012720:Severity of Illness Index; D055105:Waist Circumference
keywords: BMI; children; morbid obesity; reference values