title: Design of the OPUS School Meal Study: a randomised controlled trial assessing the impact of serving school meals based on the New Nordic Diet.
abstract: BACKGROUND
  Danish children consume too much sugar and not enough whole grain, fish, fruit, and vegetables. The Nordic region is rich in such foods with a strong health-promoting potential. We lack randomised controlled trials that investigate the developmental and health impact of serving school meals based on Nordic foods.
  
  
  OBJECTIVE
  This paper describes the rationale, design, study population, and potential implications of the Optimal well-being, development and health for Danish children through a healthy New Nordic Diet (OPUS) School Meal Study.
  
  
  METHODS
  In a cluster-randomised cross-over design, 1021 children from 3rd and 4th grades (8-11 years old) at nine Danish municipal schools were invited to participate. Classes were assigned to two 3-month periods with free school meals based on the New Nordic Diet (NND) or their usual packed lunch (control). Dietary intake, nutrient status, physical activity, cardiorespiratory fitness, sleep, growth, body composition, early metabolic and cardiovascular risk markers, illness, absence from school, wellbeing, cognitive function, social and cultural features, food acceptance, waste, and cost were assessed.
  
  
  RESULTS
  In total, 834 children (82% of those invited) participated. Although their parents were slightly better educated than the background population, children from various socioeconomic backgrounds were included. The proportion of overweight and obese children (14%) resembled that of earlier examinations of Danish school children. Drop out was 8.3%.
  
  
  CONCLUSIONS
  A high inclusion rate and low drop out rate was achieved. This study will be the first to determine whether school meals based on the NND improve children's diet, health, growth, cognitive performance, and early disease risk markers.
authors.affiliation: Department of Human Nutrition, Faculty of Science, University of Copenhagen, Denmark. ctd@life.ku.dk
authors.forename: Camilla T
authors.initials: CT
authors.lastname: Damsgaard
authors.forename: Stine-Mathilde
authors.initials: SM
authors.lastname: Dalskov
authors.forename: Rikke A
authors.initials: RA
authors.lastname: Petersen
authors.forename: Louise B
authors.initials: LB
authors.lastname: Sørensen
authors.forename: Christian
authors.initials: C
authors.lastname: Mølgaard
authors.forename: Anja
authors.initials: A
authors.lastname: Biltoft-Jensen
authors.forename: Rikke
authors.initials: R
authors.lastname: Andersen
authors.forename: Anne V
authors.initials: AV
authors.lastname: Thorsen
authors.forename: Inge
authors.initials: I
authors.lastname: Tetens
authors.forename: Anders
authors.initials: A
authors.lastname: Sjödin
authors.forename: Mads F
authors.initials: MF
authors.lastname: Hjorth
authors.forename: Ditte
authors.initials: D
authors.lastname: Vassard
authors.forename: Jørgen D
authors.initials: JD
authors.lastname: Jensen
authors.forename: Niels
authors.initials: N
authors.lastname: Egelund
authors.forename: Camilla B
authors.initials: CB
authors.lastname: Dyssegaard
authors.forename: Ib
authors.initials: I
authors.lastname: Skovgaard
authors.forename: Arne
authors.initials: A
authors.lastname: Astrup
authors.forename: Kim F
authors.initials: KF
authors.lastname: Michaelsen
mesh_terms: D002648:Child; D002664:Child Nutritional Physiological Phenomena / Q000502:physiology*; D016000:Cluster Analysis; D018592:Cross-Over Studies; D003718:Denmark; D004032:Diet / Q000592:standards*; D005260:Female; D005522:Food Services / Q000592:standards*; D006801:Humans; D008297:Male; D018673:Nutrition Policy; D012107:Research Design; D012574:Schools