Ken K L Ong, Marion L Ahmed, Pauline M Emmett, Michael A Preece, David B Dunger
Ong K K L, Ahmed M L, Emmett P M, Preece M A, Dunger D B.
Association between postnatal catch-up growth and obesity in childhood: prospective cohort study
BMJ 2000; 320 :967
doi:10.1136/bmj.320.7240.967
Catch up growth or poverty?
Dear Editor,
We are writing in response to Ong et al’s paper (1)regarding the
association between postnatal catch-up growth and obesity in children up
to 5 years. The results showed that there was significant catch-up in a
high proportion of low birth weight babies, and that this was associated
with obese children at 5 years. The authors conclude that the
relationship between low birth weight, catch-up growth and obesity at 5
years is causal. We question the validity of this conclusion because the
authors have not taken into account all of the factors that could
influence growth in infants or children.
In particular, dietary factors and socio-economic class were
apparently not measured. These factors have been linked to low birth
weight and obesity in children in other studies (2-4). The results could
be explained by low socio-economic status, perhaps through poor nutrition
and smoking in pregnancy, both causing low birth weight. Moreover, in
lower socio-economic groups, overfeeding with fatty foods in infancy or
childhood may explain the catch-up growth and obesity reported in this
study.
Unfortunately, the authors have not adjusted their analyses for any
measure of socio-economic status or nutritional intake. The conclusions
would have been more convincing if these factors had been taken into
account.
Yours sincerely
Rose CJ, Abdennadher JL, Hassan MA, Ugwu P
3rd Year Medical Students
Department of Epidemiology and Public Health,
University of Newcastle Upon Tyne
Competing interests: No competing interests