title: Dietary restraint is non-genetically associated with change in body mass index: the Healthy Twin Study.
abstract: OBJECTIVE
  We aimed to examine if past and more recent body mass index (BMI) changes are associated with eating behavior (EB) traits and whether these associations are due to non-genetic factors.
  
  
  METHODS
  In 1321 Korean twins and family members, recent and past BMI change groups were defined using quartiles of BMI change between first and second visits over 2.4±0.9 years and BMI change between 20 years old and second visit, respectively. We applied linear mixed analysis for relationships of past or recent BMI change groups and each EB (restrained, external, and emotional EB using the Dutch Eating Behavior Questionnaire) assessed at second visit after adjusting for household effect and covariates (age, gender, education, medical history of diabetes, hypertension, and dyslipidemia, alcohol use, physical activity, smoking habit, and calorie intake). In monozygotic twin pairs, paired t-test for within-pair comparison and conditional logistic regression analysis were conducted regarding EB.
  
  
  RESULTS
  Greater past BMI change was associated with higher restrained eating scores (P for trend=0.031), whereas greater recent BMI change was associated with higher external eating scores (P for trend=0.046). In co-twin-control analysis, twins with greater past BMI change were more likely to have higher restrained eating scores as compared with their co-twins with lower past BMI change (odds ratio 1.80; 95% confidence interval 1.13-2.87), whereas there were no associations between recent BMI change and external eating scores.
  
  
  CONCLUSIONS
  Greater BMI change since 20 years old is associated with higher dietary restraint, and non-genetic factors explain this relationship.
authors: Department of Epidemiology, School of Public Health and Institute of Health and Environment, Seoul National University, Seoul, Korea.
authors: Joohon
authors: J
authors: Sung
authors: Department of Family Medicine, Busan Paik Hospital, Inje University College of Medicine, Busan, Korea. kayoung.fmlky@gmail.com.
authors: Kayoung
authors: K
authors: Lee
authors: Department of Family Medicine, Samsung Medical Center and Center for Clinical Research, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors: Yun-Mi
authors: YM
authors: Song
mesh_terms: D000328:Adult; D000368:Aged; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011795:Surveys and Questionnaires; D014430:Twins, Monozygotic
keywords: BMI change; Dietary restraint; non-genetic factor; twin