title: Body mass index and subjective well-being in young adults: a twin population study.
abstract: BACKGROUND
  Body mass index (BMI) is associated with subjective well-being. Higher BMI is believed to be related with lower well-being. However, the association may not be linear. Therefore, we investigated whether a nonlinear (U-shaped) trend would better describe this relationship, and whether eating disorders might account for the association in young adults.
  
  
  METHODS
  FinnTwin16 study evaluated multiple measures of subjective well-being, including life satisfaction, General Health Questionnaire (GHQ-20), satisfaction with leisure time, work, and family relationships, and satisfaction with sex life in young adulthood in the 1975-79 birth cohorts of Finnish twins (n=5240). We studied the relationship between indicators of subjective well-being and BMI both in full birth cohorts and in subgroups stratified by lifetime DSM-IV eating disorders.
  
  
  RESULTS
  We found an inverse U-shaped relationship between all indicators of subjective well-being and BMI in men. There was no overall association between BMI and subjective well-being in women. However, there was an inverse U-shaped relationship between BMI and indicators of subjective well-being in women with a lifetime eating disorder and their healthy female co-twins. Subjective well-being was optimal in the overweight category.
  
  
  CONCLUSIONS
  Both underweight and obesity are associated with impaired subjective well-being in young men. The BMI reflecting optimal subjective well-being of young men may be higher than currently recognized. Categorization of body weight in terms of BMI may need to be reassessed in young men. BMI and subjective well-being are related in women with a lifetime eating disorder, but not in the general population of young women.
authors.affiliation: Hjelt Institute, Department of Public Health, University of Helsinki, Helsinki, Finland. milla.linna@helsinki.fi
authors.forename: Milla S
authors.initials: MS
authors.lastname: Linna
authors.forename: Jaakko
authors.initials: J
authors.lastname: Kaprio
authors.forename: Anu
authors.initials: A
authors.lastname: Raevuori
authors.forename: Elina
authors.initials: E
authors.lastname: Sihvola
authors.forename: Anna
authors.initials: A
authors.lastname: Keski-Rahkonen
authors.forename: Aila
authors.initials: A
authors.lastname: Rissanen
mesh_terms: D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D004200:Diseases in Twins / Q000453:epidemiology*; D001068:Feeding and Eating Disorders / Q000453:epidemiology; D005260:Female; D005387:Finland; D006304:Health Status; D006801:Humans; D008297:Male; D011795:Surveys and Questionnaires; D014427:Twins; D055815:Young Adult