title: Body mass index and suicidal behaviors: a critical review of epidemiological evidence.
abstract: BACKGROUND
  Obesity has been associated with an elevated risk of depression and other mental health symptoms. An increasing number of robust prospective studies, however, counter-intuitively and consistently suggested that body mass index (BMI) was inversely associated with the risk of completed suicide in a dose-response fashion. The current contribution appraised the epidemiological evidence and examined the nature of the purported relationship.
  
  
  METHODS
  We conducted a systematic review of English publications of original studies using the terms "obesity", "overweight", "body mass index", "BMI", "attempted suicide", "completed suicide", "suicide ideation", "suicidal behaviors" and "suicide". Data were extracted primarily through MEDLINE and PUBMED databases.
  
  
  RESULTS
  Almost all cohort studies reported an inverse relationship between BMI and the risk of completed suicide irrespective of region of origin and the gender of study participants. Overall, among men, a high BMI was associated with a low risk of attempted or completed suicide. There was a paradox among women, namely, a high BMI was associated with an elevated risk of attempted suicide but a low risk of completed suicide.
  
  
  CONCLUSIONS
  As a narrative review, the current report was interpretive and qualitative in nature.
  
  
  CONCLUSIONS
  Consideration of observational data, methodological issues stemmed from the rarity of deaths by suicide, homogeneity of study populations, heterogeneity of suicide methods, and the corresponding neurobiological changes made interpretation difficult. Intercultural cohort observations across countries may help to weigh the contributions from biological and socio-cultural factors. The purported association not only represents a scientific challenge, it's also an opportunity potentially leading to important insights into prevention of suicide death.
authors.affiliation: Division of epidemiology, Jiann-Ping Hsu College of Public Health, Georgia Southern University, PO box 8015 Statesboro, GA 30465, USA. jianzhang@georgiasouthern.edu
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.forename: Fei
authors.initials: F
authors.lastname: Yan
authors.forename: Yanfeng
authors.initials: Y
authors.lastname: Li
authors.forename: Robert E
authors.initials: RE
authors.lastname: McKeown
mesh_terms: D015992:Body Mass Index; D015331:Cohort Studies; D006801:Humans; D012306:Risk; D013405:Suicide / Q000523:psychology* / Q000706:statistics & numerical data