title: Association between the seven-repeat allele of the dopamine-4 receptor gene (DRD4) and spontaneous food intake in pre-school children.
abstract: BACKGROUND
  Studies in adults show associations between the hypofunctional seven-repeat allele (7R) of the dopamine-4 receptor gene (DRD4), increased eating behaviour and/or obesity, particularly in females. We examined whether 7R is associated with total caloric intake and/or food choices in pre-schoolers.
  
  
  METHODS
  150 four-year-old children taking part in a birth cohort study in Canada were administered a snack test meal in a laboratory setting. Mothers also filled out a food frequency questionnaire to address childrens' habitual food consumption. Total caloric and individual macronutrient intakes during the snack meal and specific types of foods as reported in the food diaries were compared across 7R allele carriers vs. non-carriers, using current BMI as a co-variate.
  
  
  RESULTS
  We found significant sex by genotype interactions for fat and protein intake during the snack test. Post hoc testing revealed that in girls, but not boys, 7R carriers ate more fat and protein than did non-carriers. Based on the food diaries, across both sexes, 7R carriers consumed more portions of ice cream and less vegetables, eggs, nuts and whole bread, suggesting a less healthy pattern of habitual food consumption.
  
  
  CONCLUSIONS
  The 7R allele of DRD4 influences macronutrient intakes and specific food choices as early as four years of age. The specific pattern of results further suggests that prior associations between the 7R allele and adult overeating/obesity may originate in food choices observable in the preschool years. Longitudinal follow-up of these children will help establish the relevance of these findings for obesity risk and prevention.
authors.affiliation: Department of Psychiatry and Neurology, McGill University, Douglas Mental Health University Institute, Canada; Departamento de Pediatria, Faculdade de Medicina, Universidade Federal do Rio Grande do Sul Ramiro Barcelos, 2350 Largo Eduardo Zaccaro Faraco, 90035-903 Porto Alegre, RS, Brazil. Electronic address: 00032386@ufrgs.br.
authors.forename: Patrícia Pelufo
authors.initials: PP
authors.lastname: Silveira
authors.affiliation: Department of Psychiatry and Neurology, McGill University, Douglas Mental Health University Institute, Canada.
authors.forename: André Krumel
authors.initials: AK
authors.lastname: Portella
authors.affiliation: Department of Psychiatry, University of Toronto and Centre for Addiction and Mental Health, Canada.
authors.forename: James L
authors.initials: JL
authors.lastname: Kennedy
authors.affiliation: Department of Psychiatry and Neurology, McGill University, Douglas Mental Health University Institute, Canada.
authors.forename: Hélène
authors.initials: H
authors.lastname: Gaudreau
authors.affiliation: Department of Kinesiology and Health Sciences, York University, Canada.
authors.forename: Caroline
authors.initials: C
authors.lastname: Davis
authors.affiliation: Department of Psychiatry and Behavioural Neurosciences, McMaster University, Canada.
authors.forename: Meir
authors.initials: M
authors.lastname: Steiner
authors.affiliation: Department of Psychiatry and Behavioural Neurosciences, McMaster University, Canada.
authors.forename: Claudio N
authors.initials: CN
authors.lastname: Soares
authors.affiliation: Department of Physiology, Obstetrics & Gynecology and Medicine, University of Toronto, Canada.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Matthews
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada; Institute for Human Development, University of Toronto, Toronto, ON, Canada.
authors.forename: Marla B
authors.initials: MB
authors.lastname: Sokolowski
authors.affiliation: Department of Management, McGill University, Canada.
authors.forename: Laurette
authors.initials: L
authors.lastname: Dubé
authors.affiliation: Department of Community Health, Epidemiology Section, Center for Clinical Epidemiology and Population Health, Brown University, United States.
authors.forename: Eric B
authors.initials: EB
authors.lastname: Loucks
authors.affiliation: Hospital for Sick Children, University of Toronto, Toronto, Canada.
authors.forename: Jill
authors.initials: J
authors.lastname: Hamilton
authors.affiliation: Department of Psychiatry and Neurology, McGill University, Douglas Mental Health University Institute, Canada; Singapore Institute for Clinical Sciences, The Agency for Science, Technology and Research, Singapore.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Meaney
authors.affiliation: Department of Psychiatry, University of Toronto and Centre for Addiction and Mental Health, Canada.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Levitan
mesh_terms: D000483:Alleles; D015992:Body Mass Index; D002170:Canada; D002675:Child, Preschool; D004032:Diet; D004435:Eating; D002149:Energy Intake / Q000235:genetics*; D005247:Feeding Behavior; D005260:Female; D005518:Food Preferences; D005838:Genotype; D006801:Humans; D006963:Hyperphagia / Q000235:genetics; D008297:Male; D009765:Obesity / Q000235:genetics*; D050638:Receptors, Dopamine D4 / Q000235:genetics*; D012737:Sex Factors; D062410:Snacks
chemical_list: D050638:Receptors, Dopamine D4
keywords: Child behavior; DRD4; Dopamine; Feeding behavior; Food intake; Reward