Currently health officials are attempting to better monitor the diets of school-age children to stem the rise in overweight. But the new study suggests that public health campaigns may need to focus on obesity prevention among children even earlier.
Dr Janis Baird, at the University of Southampton in the UK and colleagues analysed 24 studies which assessed the relation between infant size and growth and the development of obesity at any later age.
The heaviest infants, those with the highest body mass index, and those who gained weight rapidly during the first and second year of life, were more likely to be obese in childhood, adolescence, and early adulthood than other infants, they report in the latest issue of the British Medical Journal (doi:10.1136/bmj.38586.411273.EO).
Out of 18 that assessed the relation between infant size and subsequent obesity, those who had been obese had a relative risk for subsequent obesity of between 1.35 and 9.38.
In the 10 studies looking at the relation of infant growth with subsequent obesity, most showed that infants who grew more rapidly were at increased risk of obesity. Compared with other infants, in infants with rapid growth odds ratios and relative risks of later obesity ranged from 1.17 to 5.70.
Future studies should investigate what determines these patterns of growth, and to explore whether interventions to alter infant growth could be associated with other benefits or harms, write the authors.
A major trial on European children is currently looking at how early childhood diet can reduce the risk of obesity in later life.
Baird's team says it will also be important to assess whether factors influencing infant growth are amenable to change and acceptable to parents.