title: Cross-sectional and longitudinal associations between energy intake and BMI z-score in European children.
abstract: BACKGROUND
  Evidence for the effect of dietary energy on BMI z-scores in young children is limited. We aim to investigate cross-sectional and longitudinal effects of daily energy intake (EI) on BMI z-scores of European boys and girls considering growth-related height dependencies of EI using residual EI.
  
  
  METHODS
  To investigate cross-sectional and longitudinal effects of daily energy intake (EI) on BMI z-scores of European boys and girls considering growth-related height dependencies of EI using residual EI.
  
  
  METHODS
  Subjects were children aged 2- < 10 y old (N = 2753, 48.2% girls) participating in the IDEFICS (Identification and prevention of Dietary- and lifestyle-induced health EFfects In Children and infantS) baseline and follow-up examination. Usual EI (kcal/day) was calculated based on the National Cancer Institute-method excluding subjects with implausible reported EI. Effect of age, height and sex-adjusted residuals of EI on BMI z-score was investigated stratified by baseline age -group (2- < 4 y, 4- < 6 y, 6- < 8 y and 8- < 10 y) cross-sectionally using linear regression models adjusted for relevant confounders (crude model: age, sex, country; fully adjusted model: plus parental ISCED level, parental BMI, screen time; subgroup analysis: plus objectively measured physical activity). Longitudinal associations were estimated between changes in (Δ) residual EI per year and ΔBMI z-score per year with adjustments analogously to the cross-sectional models but with additional adjustment for residual EI at baseline.
  
  
  RESULTS
  Cross-sectionally, positive associations were observed between residual EI and BMI z-score for the full study sample, for boys and in older (≥6 years) but not in younger children in the crude and fully adjusted model. Longitudinally, small positive associations were observed between Δresidual EI per y on ΔBMI z-score per y for the full study sample and in 4- < 6 y olds in the crude and fully adjusted model.
  
  
  CONCLUSIONS
  In conclusion, EI above the average intakes for a certain sex, age and height are weakly associated with BMI z-scores in European children. Residual EI may be considered as a useful exposure measure in children as it accounts for growth-related changes in usual EI during childhood.
authors.affiliation: Leibniz-Institute for Prevention Research and Epidemiology - BIPS GmbH, Achterstr. 30, D-28359, Bremen, Germany. hebestr@bips.uni-bremen.de.
authors.forename: Antje
authors.initials: A
authors.lastname: Hebestreit
authors.affiliation: Institute of Food Sciences, National Research Council, Avellino, Italy.
authors.forename: Gianvincenzo
authors.initials: G
authors.lastname: Barba
authors.affiliation: Department of Public Health, Ghent University, Ghent, Belgium. stefaan.dehenauw@ugent.be.
authors.forename: Stefaan
authors.initials: S
authors.lastname: De Henauw
authors.affiliation: Department of Public Health and Community Medicine, University of Gothenburg, Gothenburg, Sweden. gabriele.eiben@medfak.gu.se.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Eiben
authors.affiliation: Research and Education Institute of Child Health, Strovolos, Cyprus. chadjigeo@mtnmail.com.cy.
authors.forename: Charalampos
authors.initials: C
authors.lastname: Hadjigeorgiou
authors.affiliation: Department of Pediatrics, University of Pécs, Pécs, Hungary and Institute for Medical Information Processing, Biometrics and Epidemiology and German Centre for Vertigo and Balance Disorders, Ludwig Maximilian University, Munich, Germany. e.k.kovacs@gmail.com.
authors.forename: Éva
authors.initials: É
authors.lastname: Kovács
authors.affiliation: Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. Vittorio.Krogh@istitutotumori.mi.it.
authors.forename: Vittorio
authors.initials: V
authors.lastname: Krogh
authors.affiliation: GENUD (Growth, Exercise, Nutrition and Development) Research Group, Faculty of Health Sciences, University of Zaragoza, Zaragoza, Spain. lmoreno@unizar.es.
authors.forename: Luis A
authors.initials: LA
authors.lastname: Moreno
authors.affiliation: Department of Preventive and Predictive Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy. Valeria.Pala@istitutotumori.mi.it.
authors.forename: Valeria
authors.initials: V
authors.lastname: Pala
authors.affiliation: Department of Chronic Diseases, National Institute for Health Development, Tallinn, Estonia. toomas.veidebaum@tai.ee.
authors.forename: Toomas
authors.initials: T
authors.lastname: Veidebaum
authors.affiliation: Leibniz-Institute for Prevention Research and Epidemiology - BIPS GmbH, Achterstr. 30, D-28359, Bremen, Germany. wolters@bips.uni-bremen.de.
authors.forename: Maike
authors.initials: M
authors.lastname: Wolters
authors.affiliation: Leibniz-Institute for Prevention Research and Epidemiology - BIPS GmbH, Achterstr. 30, D-28359, Bremen, Germany. boern@bips.uni-bremen.de.
authors.forename: Claudia
authors.initials: C
authors.lastname: Börnhorst
mesh_terms: D015992:Body Mass Index; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D004032:Diet / Q000706:statistics & numerical data; D002149:Energy Intake / Q000502:physiology*; D005060:Europe; D015444:Exercise; D005260:Female; D006306:Health Surveys / Q000706:statistics & numerical data*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011446:Prospective Studies; D011795:Surveys and Questionnaires