title: Protein intake in early childhood and body composition at the age of 6 years: The Generation R Study.
abstract: Previous studies suggest that high protein intake in infancy leads to a higher body mass index (BMI) in later childhood. We examined the associations of total, animal and vegetable protein intake in early childhood with detailed measures of body composition at the age of 6 years.
  
  
  
  This study was performed in 2911 children participating in a population-based cohort study. Protein intake at the age of 1 year was assessed with a validated food-frequency questionnaire and was adjusted for total energy intake. At the children's age of 6 years, we measured their anthropometrics and body fat (with dual-energy X-ray absorptiometry). We calculated age- and sex-specific s.d. scores for BMI, fat mass index (FMI) and fat-free mass index (FFMI).
  
  
  
  After adjustment for confounders, a 10 g per day higher total protein intake at 1 year of age was associated with a 0.05 s.d. (95% confidence interval (CI) 0.00, 0.09) higher BMI at age 6. This association was fully driven by a higher FMI (0.06 s.d. (95%CI 0.01, 0.11)) and not FFMI (-0.01 s.d. (95%CI -0.06, 0.05)). The associations of protein intake with FMI at 6 years remained significant after adjustment for BMI at the age of 1 year. Additional analyses showed that the associations of protein intake with FMI were stronger in girls than in boys (P for interaction=0.03), stronger among children who had catch-up growth in the first year of life (P for interaction<0.01) and stronger for intake of animal protein (both dairy and non-dairy protein) than protein from vegetable sources.
  
  
  
  Our results suggest that high protein intake in early childhood is associated with higher body fat mass, but not fat-free mass. Future studies are needed to investigate whether these changes persist into adulthood and to examine the optimal range of protein intake for infants and young children.
authors.affiliation: The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: T
authors.initials: T
authors.lastname: Voortman
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: K V E
authors.initials: KV
authors.lastname: Braun
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|Leiden University College, The Hague, The Netherlands.
authors.forename: J C
authors.initials: JC
authors.lastname: Kiefte-de Jong
authors.affiliation: The Generation R Study Group, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.|Department of Pediatrics, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: V W V
authors.initials: VW
authors.lastname: Jaddoe
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: O H
authors.initials: OH
authors.lastname: Franco
authors.affiliation: Department of Epidemiology, Erasmus MC, University Medical Center, Rotterdam, The Netherlands.
authors.forename: E H
authors.initials: EH
authors.lastname: van den Hooven
mesh_terms: D001823:Body Composition / Q000187:drug effects*; D015992:Body Mass Index; D002648:Child; D002664:Child Nutritional Physiological Phenomena / Q000187:drug effects*; D004044:Dietary Proteins / Q000008:administration & dosage* / Q000494:pharmacology*; D002149:Energy Intake; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D015596:Nutrition Assessment; D063766:Pediatric Obesity / Q000453:epidemiology / Q000517:prevention & control; D011446:Prospective Studies
chemical_list: D004044:Dietary Proteins