Infant growth and later body composition: evidence from the 4-component model.
BACKGROUND
Rapid weight gain in infancy is associated with higher body mass index in later life, but its relation with individual body-composition components remains unclear.


OBJECTIVE
We aimed to investigate associations between weight gain during different periods in infancy and later fat mass (FM) and fat-free mass (FFM).


METHODS
Body composition was assessed by using the 4-component model, dual-energy X-ray absorptiometry, and anthropometry in 234 healthy UK children and adolescents (105 boys; x +/- SD age: 11.4 +/- 3.8 y). Early growth measurements were prospective in 52 subjects and retrospective in 182. Relative weight gain was calculated as change in SD score (SDS) during different periods.


RESULTS
Relative weight gain from 0 to 3 mo and from 3 to 6 mo showed positive relations with childhood FM, waist circumference, and trunk FM that were equivalent to increases in FMI (FM/height(2)) of 0.24 SDS (95% CI: 0.04, 0.44) and 0.50 SDS (0.25, 0.75) per 1-SDS increase in early weight and that were comparable to the effect of current obesity risk factors. Relative weight gain from 0 to 3 mo was also positively associated with later FFMI (FFM/height(2)). Relative weight gain from 6 to 12 mo was not associated with later body composition. Associations were independent of birth weight, sex, puberty, physical activity, socioeconomic class, ethnicity, and parental body mass index.


CONCLUSIONS
In this Western population, greater relative weight gain during early infancy was positively associated with later FM and central fat distribution and with FFM. Rapid weight gain in infancy may be a risk factor for later adiposity. Early infancy may provide an opportunity for interventions aimed at reducing later obesity risk.
Chomtho
Sirinuch
S
The Medical Research Council, Childhood Nutrition Research Centre, Institute of Child Health, University College London, London, United Kingdom. s.chomtho@ich.ucl.ac.uk
Wells
Jonathan Ck
JC
Williams
Jane E
JE
Davies
Peter Sw
PS
Lucas
Alan
A
Fewtrell
Mary S
MS
D015502:Absorptiometry, Photon; D000273:Adipose Tissue / Q000033:anatomy & histology; D001724:Birth Weight; D001823:Body Composition; D015992:Body Mass Index; D003903:Deuterium; D004739:England; D006128:Growth / Q000502:physiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008954:Models, Biological; D010991:Plethysmography; D012044:Regression Analysis; D012574:Schools; D015430:Weight Gain / Q000502:physiology*
D003903:Deuterium