ORIGINAL ARTICLE Feeding practices in pregnancy and infancy: relationship with the development of overweight and obesity in childhood SM Robinson and KM Godfrey MRC Epidemiology Resource Centre, University of Southampton, Southampton General Hospital, Southampton, UK The number of overweight children is increasing rapidly, and there is an urgent need to identify the risk factors for obesity, with a view to preventing further increases in prevalence. Experimental studies in animals and preliminary observations in humans suggest that early experience may influence later risk of obesity, but we do not yet understand the extent to which early influences affect individual vulnerability to risk factors acting later in life. In the developed world, few studies have examined whether current variations in maternal diet have long-term effects on children’s body composition. Rapid postnatal growth is associated with greater adiposity, but the role of variations in infant diet and the mechanisms involved are not understood, and there may be interactive effects of early diet and growth rate on body composition. Familial concordance in obesity prevalence suggests that the shared food environment is of key importance. Early life may be a time when dietary practices are established that will continue throughout childhood. Further research is needed to gain insight into the evolution of dietary habits in childhood and to determine how these practices influence obesity risk. International Journal of Obesity (2008) 32, S4–S10; doi:10.1038/ijo.2008.201 Keywords: childhood obesity; developmental influences; dietary practice Introduction During the past two decades the prevalence of overweight in children has risen dramatically, such that 10% of school-age children worldwide are currently estimated to be either overweight or obese. 1 Although the prevalence of over- weight is higher in economically developed regions, where it is arguably becoming the primary childhood health pro- blem, 2 it is rising significantly in most parts of the world. 1 Apart from the increased likelihood of these overweight children remaining overweight in adolescence and in adult life, 3,4 there are direct consequences of being overweight in childhood that are now being seen. 1 For example, the emergence of type 2 diabetes in adolescence, accounting for more than a third of diabetes in some ethnic groups studied, 5 has been attributed largely to the paediatric obesity epidemic. 2 Being an overweight child may also have consequences for psychological well-being. 6 When com- pared with children of normal weight, overweight children have been shown to have lower health-related quality of life, 7 and educational and social outcomes of overweight adolescents are poorer. 8,9 Thus the long-term costs of the increasing prevalence of overweight and obesity in child- hood cannot be considered simply in terms of the individual burden on health, but will also have societal and economic implications. Influences on the development of childhood overweight The development of overweight depends on a mismatch of energy intake to energy need over a prolonged period. Although twin studies show clear concordance in parent and child body mass index (BMI), 10,11 indicating the importance of the genetic contribution to the regulation of body weight, estimates of the heritability of obesity vary widely. 12 The current rate of change in the prevalence of overweight and obesity in childhood together with differing rates of obesity observed among genetically similar adult populations living in different settings 1 show that irrespective of the exact estimate of heritability, that environmental factors make a major contribution to the development of obesity. Clearly, understanding the role of these factors in the aetiology of Correspondence: Dr SM Robinson, MRC Epidemiology Resource Centre, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK. E-mail: smr@mrc.soton.ac.uk International Journal of Obesity (2008) 32, S4–S10 & 2008 Macmillan Publishers Limited All rights reserved 0307-0565/08 $32.00 www.nature.com/ijo