The prevalence of obesity among children is high and is increasing. We
know that obesity runs in families, with children of obese parents at
greater risk of developing obesity than children of thin parents. Res
earch on genetic factors in obesity has provided us with estimates of
the proportion of the variance in a population accounted for by geneti
c factors. However, this research does not provide information regardi
ng individual development To design effective preventive interventions
, research is needed to delineate how genetics and environmental facto
rs interact in the etiology of childhood obesity. Addressing this ques
tion is especially challenging because parents provide both genes and
environment for children. An enormous amount of learning about food an
d eating occurs during the transition from the exclusive milk diet of
infancy to the omnivore's diet consumed by early childhood. This early
learning is constrained by children's genetic predispositions, which
include the unlearned preference for sweet tastes, salty tastes, and t
he rejection of sour and bitter tastes. Children also are predisposed
to reject new foods and to learn associations between foods' flavors a
nd the postingestive consequences of eating. Evidence suggests that ch
ildren can respond to the energy density of the diet and that although
intake at individual meals is erratic, 24-hour energy intake is relat
ively well regulated. There are individual differences in the regulati
on of energy intake as early as the preschool period. These individual
differences in self-regulation are associated with differences in chi
ld-feeding practices and with children's adiposity. This suggests that
child-feeding practices have the potential to affect children's energ
y balance via altering patterns of intake. Initial evidence indicates
that imposition of stringent parental controls can potentiate preferen
ces for high-fat, energy-dense foods, limit children's acceptance of a
variety of foods, and disrupt children's regulation of energy intake
by altering children's responsiveness to internal cues of hunger and s
atiety. This can occur when well-intended but concerned parents assume
that children need help in determining what, when, and how much to ea
t and when parents impose child-feeding practices that provide childre
n with few opportunities for self-control. Implications of these findi
ngs for preventive interventions are discussed.