title: Is thinness more prevalent than obesity in Portuguese adolescents?
abstract: OBJECTIVE
  There is little information regarding the prevalence of thinness in European adolescents. This was assessed in a convenience sample of children and adolescents from the Lisbon area (Portugal).
  
  
  METHODS
  Cross-sectional study including 2494 boys and 2519 girls aged 10-18 years. Body mass index (BMI), waist and hip were measured using standardized methods; thinness was defined using international criteria. Body fat was assessed by bioelectrical impedance.
  
  
  RESULTS
  In girls, prevalence of thinness, overweight and obesity were 5.6%, 19.7% and 4.7%, respectively, whereas the corresponding numbers in boys were 3.9%, 17.4% and 5.3%. Prevalence of thinness increased whereas obesity decreased with age: from 1.5% to 7.6% for thinness and from 9.2% to 3.8% for obesity in girls aged 10 and 18, respectively. In boys, the corresponding trends were from 0% to 7.3% for thinness and from 10.6% to 3% for obesity. After adjusting for age, differences were found between BMI groups for weight, body fat percentage, fat mass, lean mass, waist and hip, while no differences regarding height were found between thin and normal weight participants.
  
  
  CONCLUSIONS
  The prevalence of thinness is more frequent than obesity after age 14 in girls and 16 years in boys. Thinness is associated with a decreased body weight and body fat, whereas no consistent effect on height was noted.
authors.affiliation: Cardiomet, 21 rue du Bugnon, 1005 Lausanne, Switzerland. pedro-manuel.marques-vidal@chuv.ch
authors.forename: Pedro
authors.initials: P
authors.lastname: Marques-Vidal
authors.forename: Raquel
authors.initials: R
authors.lastname: Ferreira
authors.forename: João Miguel
authors.initials: JM
authors.lastname: Oliveira
authors.forename: Fred
authors.initials: F
authors.lastname: Paccaud
mesh_terms: D000273:Adipose Tissue / Q000378:metabolism*; D000293:Adolescent; D017195:Adolescent Nutritional Physiological Phenomena / Q000502:physiology*; D000367:Age Factors; D001827:Body Height / Q000502:physiology; D015992:Body Mass Index; D002648:Child; D003430:Cross-Sectional Studies; D017097:Electric Impedance; D005260:Female; D006801:Humans; D008297:Male; D009752:Nutritional Status; D009765:Obesity / Q000453:epidemiology*; D011174:Portugal / Q000453:epidemiology; D015995:Prevalence; D013851:Thinness / Q000453:epidemiology*; D049629:Waist-Hip Ratio