title: Effects of promoting longer-term and exclusive breastfeeding on adiposity and insulin-like growth factor-I at age 11.5 years: a randomized trial.
abstract: OBJECTIVE
  Evidence that longer-term and exclusive breastfeeding reduces child obesity risk is based on observational studies that are prone to confounding.
  
  
  OBJECTIVE
  To investigate effects of an intervention to promote increased duration and exclusivity of breastfeeding on child adiposity and circulating insulin-like growth factor (IGF)-I, which regulates growth.
  
  
  METHODS
  Cluster-randomized controlled trial in 31 Belarusian maternity hospitals and their affiliated clinics, randomized into 1 of 2 groups: breastfeeding promotion intervention (n = 16) or usual practices (n = 15). Participants were 17,046 breastfeeding mother-infant pairs enrolled in 1996 and 1997, of whom 13,879 (81.4%) were followed up between January 2008 and December 2010 at a median age of 11.5 years.
  
  
  METHODS
  Breastfeeding promotion intervention modeled on the WHO/UNICEF Baby-Friendly Hospital Initiative (World Health Organization/United Nations Children's Fund).
  
  
  METHODS
  Body mass index (BMI), fat and fat-free mass indices (FMI and FFMI), percent body fat, waist circumference, triceps and subscapular skinfold thicknesses, overweight and obesity, and whole-blood IGF-I. Primary analysis was based on modified intention-to-treat (without imputation), accounting for clustering within hospitals and clinics.
  
  
  RESULTS
  The experimental intervention substantially increased breastfeeding duration and exclusivity when compared with the control (43% vs 6% exclusively breastfed at 3 months and 7.9% vs 0.6% at 6 months). Cluster-adjusted mean differences in outcomes at 11.5 years of age between experimental vs control groups were: 0.19 (95% CI, -0.09 to 0.46) for BMI; 0.12 (-0.03 to 0.28) for FMI; 0.04 (-0.11 to 0.18) for FFMI; 0.47% (-0.11% to 1.05%) for percent body fat; 0.30 cm (-1.41 to 2.01) for waist circumference; -0.07 mm (-1.71 to 1.57) for triceps and -0.02 mm (-0.79 to 0.75) for subscapular skinfold thicknesses; and -0.02 standard deviations (-0.12 to 0.08) for IGF-I. The cluster-adjusted odds ratio for overweight/obesity (BMI ≥ 85th vs <85th percentile) was 1.18 (95% CI, 1.01 to 1.39) and for obesity (BMI ≥ 95th vs <85th percentile) was 1.17 (95% CI, 0.97 to 1.41).
  
  
  CONCLUSIONS
  AND RELEVANCE Among healthy term infants in Belarus, an intervention that succeeded in improving the duration and exclusivity of breastfeeding did not prevent overweight or obesity, nor did it affect IGF-I levels at age 11.5 years. Breastfeeding has many advantages but population strategies to increase the duration and exclusivity of breastfeeding are unlikely to curb the obesity epidemic.
  
  
  BACKGROUND
  isrctn.org: ISRCTN37687716; and clinicaltrials.gov: NCT01561612.
authors.affiliation: School of Social and Community Medicine, University of Bristol, Bristol, England. richard.martin@bristol.ac.uk
authors.forename: Richard M
authors.initials: RM
authors.lastname: Martin
authors.forename: Rita
authors.initials: R
authors.lastname: Patel
authors.forename: Michael S
authors.initials: MS
authors.lastname: Kramer
authors.forename: Lauren
authors.initials: L
authors.lastname: Guthrie
authors.forename: Konstantin
authors.initials: K
authors.lastname: Vilchuck
authors.forename: Natalia
authors.initials: N
authors.lastname: Bogdanovich
authors.forename: Natalia
authors.initials: N
authors.lastname: Sergeichick
authors.forename: Nina
authors.initials: N
authors.lastname: Gusina
authors.forename: Ying
authors.initials: Y
authors.lastname: Foo
authors.forename: Tom
authors.initials: T
authors.lastname: Palmer
authors.forename: Sheryl L
authors.initials: SL
authors.lastname: Rifas-Shiman
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Gillman
authors.forename: George Davey
authors.initials: GD
authors.lastname: Smith
authors.forename: Emily
authors.initials: E
authors.lastname: Oken
mesh_terms: D050154:Adiposity; D000328:Adult; D001942:Breast Feeding; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006293:Health Promotion; D006771:Hospitals, Maternity; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D009765:Obesity / Q000517:prevention & control*; D050177:Overweight / Q000517:prevention & control; D011247:Pregnancy; D002094:Republic of Belarus; D013997:Time Factors; D055815:Young Adult
chemical_list: D007334:Insulin-Like Growth Factor I