title: Changes in genetic risk for emotional eating across the menstrual cycle: a longitudinal study.
abstract: BACKGROUND
  Previous studies have shown significant within-person changes in binge eating and emotional eating across the menstrual cycle, with substantial increases in both phenotypes during post-ovulation. Increases in both estradiol and progesterone levels appear to account for these changes in phenotypic risk, possibly via increases in genetic effects. However, to date, no study has examined changes in genetic risk for binge phenotypes (or any other phenotype) across the menstrual cycle. The goal of the present study was to examine within-person changes in genetic risk for emotional eating scores across the menstrual cycle.
  
  
  METHODS
  Participants were 230 female twin pairs (460 twins) from the Michigan State University Twin Registry who completed daily measures of emotional eating for 45 consecutive days. Menstrual cycle phase was coded based on dates of menstrual bleeding and daily ovarian hormone levels.
  
  
  RESULTS
  Findings revealed important shifts in genetic and environmental influences, where estimates of genetic influences were two times higher in post- as compared with pre-ovulation. Surprisingly, pre-ovulation was marked by a predominance of environmental influences, including shared environmental effects which have not been previously detected for binge eating phenotypes in adulthood.
  
  
  CONCLUSIONS
  Our study was the first to examine within-person shifts in genetic and environmental influences on a behavioral phenotype across the menstrual cycle. Results highlight a potentially critical role for these shifts in risk for emotional eating across the menstrual cycle and underscore the need for additional, large-scale studies to identify the genetic and environmental factors contributing to menstrual cycle effects.
authors.affiliation: Department of Psychology,Michigan State University,East Lansing,MI,USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Klump
authors.affiliation: Department of Psychology,Michigan State University,East Lansing,MI,USA.
authors.forename: B A
authors.initials: BA
authors.lastname: Hildebrandt
authors.affiliation: Department of Psychology,Michigan State University,East Lansing,MI,USA.
authors.forename: S M
authors.initials: SM
authors.lastname: O'Connor
authors.affiliation: Department of Psychology,Florida State University,Tallahassee,FL,USA.
authors.forename: P K
authors.initials: PK
authors.lastname: Keel
authors.affiliation: Departments of Psychiatry, Human Genetics, and Psychology,Virginia Commonwealth University,Charlottesville,VA,USA.
authors.forename: M
authors.initials: M
authors.lastname: Neale
authors.affiliation: Department of Psychology,Michigan State University,East Lansing,MI,USA.
authors.forename: C L
authors.initials: CL
authors.lastname: Sisk
authors.affiliation: Department of Psychology,University of Virginia,Richmond,VA,USA.
authors.forename: S
authors.initials: S
authors.lastname: Boker
authors.affiliation: Department of Psychology,Michigan State University,East Lansing,MI,USA.
authors.forename: S A
authors.initials: SA
authors.lastname: Burt
mesh_terms: D000293:Adolescent; D000328:Adult; D002032:Bulimia / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D004644:Emotions / Q000502:physiology*; D004777:Environment; D005247:Feeding Behavior / Q000502:physiology*; D001068:Feeding and Eating Disorders / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D005260:Female; D020022:Genetic Predisposition to Disease; D006801:Humans; D008137:Longitudinal Studies; D008597:Menstrual Cycle / Q000378:metabolism*; D012042:Registries; D055815:Young Adult
keywords: Emotional eating; environmental influences; genetic influences; menstrual cycle; ovarian hormones