title: Sleep deprivation and obesity in shift workers in southern Brazil.
abstract: OBJECTIVE
  The objective of our study was to explore the association between sleep deprivation and obesity among shift workers.
  
  
  METHODS
  A cross-sectional study was conducted. Obesity was defined as BMI ≥30 kg/m2. Time of sleep was categorized as: >5 h of continuous sleep/d; ≤5 h of continuous sleep/d with some additional rest (sleep deprivation level I); and ≤5 h of continuous sleep/d without any additional rest (sleep deprivation level II). Sociodemographic, parental and behavioural variables were evaluated by means of a standardized pre-tested questionnaire. Potential confounding factors were controlled for in the multivariable model.
  
  
  METHODS
  A poultry-processing plant in southern Brazil.
  
  
  METHODS
  Nine hundred and five shift workers (63 % female).
  
  
  RESULTS
  Obesity was more prevalent in the participants who were female, aged 40 years and older, who had less schooling and reported excess weight in both parents. Sleep deprivation levels I and II were associated with increased income, number of meals consumed throughout the day and nightshift work. All of the workers who exhibited a degree of sleep deprivation worked the night shift. After controlling for potential confounding factors, the prevalence ratios of obesity were 1·4 (95 % CI 0·8, 2·2) and 4·4 (95 % CI 2·4, 8·0) in the workers with sleep deprivation levels I and II, respectively, compared with the reference group.
  
  
  CONCLUSIONS
  These results show a strong association between sleep deprivation and obesity in shift workers and that sleep deprivation may be a direct consequence of working at night.
authors.affiliation: 1Post-graduate Programme in Endocrinology,Federal University of Rio Grande do Sul State,Department of Nutrition,University of Vale do Rio dos Sinos,São Leopoldo,RS,Brazil.
authors.forename: Raquel
authors.initials: R
authors.lastname: Canuto
authors.affiliation: 2Post-graduate Programme in Collective Health,University of Vale do Rio dos Sinos,Av. Unisinos 950,CP 275,São Leopoldo,RS 93022-000,Brazil.
authors.forename: Marcos Pascoal
authors.initials: MP
authors.lastname: Pattussi
authors.affiliation: 3Department of Nursing,University of the State of Santa Catarina,Palmitos,SC,Brazil.
authors.forename: Jamile Block Araldi
authors.initials: JB
authors.lastname: Macagnan
authors.affiliation: 2Post-graduate Programme in Collective Health,University of Vale do Rio dos Sinos,Av. Unisinos 950,CP 275,São Leopoldo,RS 93022-000,Brazil.
authors.forename: Ruth Liane
authors.initials: RL
authors.lastname: Henn
authors.affiliation: 2Post-graduate Programme in Collective Health,University of Vale do Rio dos Sinos,Av. Unisinos 950,CP 275,São Leopoldo,RS 93022-000,Brazil.
authors.forename: Maria Teresa Anselmo
authors.initials: MT
authors.lastname: Olinto
mesh_terms: D000293:Adolescent; D000328:Adult; D001938:Brazil / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications / Q000453:epidemiology*; D015995:Prevalence; D012307:Risk Factors; D020178:Sleep Disorders, Circadian Rhythm / Q000150:complications / Q000453:epidemiology*; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D055815:Young Adult