title: Genetic and shared environmental influences on children's 24-h food and beverage intake: sex differences at age 7 y.
abstract: BACKGROUND
  The genetics of habitual food and beverage intake in early childhood is poorly understood.
  
  
  OBJECTIVE
  The objective was to test the magnitude of genetic and environmental influences on 24-h food and beverage intake in 7-y-old children. The association between intake of specific food-beverage categories and child body mass index (BMI; in kg/m(2)) was also tested.
  
  
  METHODS
  A classic twin design was conducted, using the MacArthur Longitudinal Study of Twins. There were 792 children, including 396 boys from 102 monozygotic and 96 dizygotic twin pairs and 396 girls from 112 monozygotic and 86 dizygotic twin pairs; Children's 24-h dietary intake was estimated by parental recall, from which 9 composite food-beverage categories were derived. Height and weight were converted to BMI. Biometrical analyses of children's daily intake of food-beverage categories and BMI were conducted.
  
  
  RESULTS
  There was consistent evidence of genetic influences on children's 24-h intake of food and beverages (servings/d), especially among boys. Seven categories showed significant heritability estimates among boys, ranging from 12% (fish and lemon) to 79% (peanut butter and jelly). Only 3 categories showed significant heritability estimates among girls, ranging from 20% (bread and butter) to 56% (fish and lemon). BMI showed a genetic correlation only with bread and butter intake in girls.
  
  
  CONCLUSIONS
  The magnitude of genetic and environmental influences on children's 24-h food and beverage intake differed for boys and girls, which suggests sex differences in the development of eating patterns. Heritability estimates were generally large, although other eating phenotypes may be necessary for identifying genetic correlations with adiposity.
authors.affiliation: Center for Weight and Eating Disorders, University of Pennsylvania School of Medicine and the The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA. mfaith@mail.med.upenn.edu
authors.forename: Myles S
authors.initials: MS
authors.lastname: Faith
authors.forename: Sally Ann
authors.initials: SA
authors.lastname: Rhea
authors.forename: Robin P
authors.initials: RP
authors.lastname: Corley
authors.forename: John K
authors.initials: JK
authors.lastname: Hewitt
mesh_terms: D001628:Beverages; D015992:Body Mass Index; D002648:Child; D002664:Child Nutritional Physiological Phenomena / Q000235:genetics* / Q000502:physiology; D015331:Cohort Studies; D004435:Eating / Q000235:genetics* / Q000502:physiology; D002149:Energy Intake / Q000235:genetics / Q000502:physiology; D004777:Environment; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D012737:Sex Factors; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic