Associations between infant feeding and the size, tempo and velocity of infant weight gain: SITAR analysis of the Gemini twin birth cohort.
OBJECTIVE
Infant growth trajectories, in terms of size, tempo and velocity, may programme lifelong obesity risk. Timing of breastfeeding cessation and weaning are both implicated in rapid infant growth; we examined the association of both simultaneously with a range of growth parameters.


METHODS
Longitudinal population-based twin birth cohort.


METHODS
The Gemini cohort provided data on 4680 UK infants with a median of 10 (interquartile range=8-15) weight measurements between birth and a median of 6.5 months. Age at breastfeeding cessation and weaning were reported by parents at mean age 8.2 months (s.d.=2.2, range=4-20). Growth trajectories were modelled using SuperImposition by Translation And Rotation (SITAR) to generate three descriptors of individual growth relative to the average trajectory: size (grams), tempo (weeks, indicating the timing of the peak growth rate) and velocity (% difference from average, reflecting mean growth rate). Complex-samples general linear models adjusting for family clustering and confounders examined associations between infant feeding and SITAR parameters.


RESULTS
Longer breastfeeding (>4 months vs never) was independently associated with lower growth velocity by 6.8% (s.e.=1.3%) and delayed growth tempo by 1.0 (s.e.=0.2 weeks), but not with smaller size. Later weaning (⩾6 months vs <4 months) was independently associated with lower growth velocity by 4.9% (s.e.=1.1%) and smaller size by 102 g (s.e.=25 g).


CONCLUSIONS
Infants breastfed for longer grew slower for longer after birth (later peak growth rate) but were no different in size, while infants weaned later grew slower overall and were smaller but the timing of peak growth did not differ. Slower trajectories with a delayed peak in growth may have beneficial implications for programming later obesity risk. Replication in cohorts with longer follow-up, alternative confounding structures or randomised controlled trials are required to confirm the long-term effects and directionality, and to rule out residual confounding.
1] Centre for Exercise, Nutrition and Health Sciences, School of Policy Studies, University of Bristol, Bristol, UK [2] Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK.
L
L
Johnson
1] Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK [2] Department of Primary Care and Public Health Sciences, King's College London, London, UK.
C H M
CH
van Jaarsveld
Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK.
C H
CH
Llewellyn
Population, Policy and Practice Programme, Institute of Child Health, University College London, London, UK.
T J
TJ
Cole
Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, UK.
J
J
Wardle
D000293:Adolescent; D001835:Body Weight; D001942:Breast Feeding; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007227:Infant Nutritional Physiological Phenomena; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D009765:Obesity / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control; D012307:Risk Factors; D014427:Twins; D006113:United Kingdom / Q000453:epidemiology; D014886:Weaning; D015430:Weight Gain