Preventing Childhood Obesity - Evidence Policy and Practice.pdf

Chapter 9
meal frequency, decreased physical activity, watching
television > 1 h/day, formula feeding and smoking in
pregnancy accounted for 48.2% of obese children aged
5 –6 years. Modification of these risk factors will potentially
yield a maximal achievable prevalence reduction
of 1.5% for obesity (3.2% observed prevalence). 19
As mothers increasingly work outside the home, the
percentage of pre - school children being cared for
outside the home has also increased. For that reason,
parents and child - care providers are sharing responsibility
in the formation of children ’ s healthy behaviors
during these important early developmental
years. Level of physical activity and quality of food in
these centers 20,21 has the potential to contribute substantially
to the observed acceleration of obesity
among preschool children attending day care centers
during the past two decades. 22 A recent review of
interventions in a variety of locations — home, day
care, preschool, and clinic — to prevent or treat obesity
among preschool children found seven studies of
which four reported significant reduction in weight
status or body fat. 23 Showing that interventions to
reduce known risk factors from pregnancy through
the early years in these settings has a great potential to
prevent overweight and obesity in early childhood.
Method
For this chapter we scanned and reviewed the published
literature (e.g., PubMed and CINAHL) to select
studies that were effective, and examined the key elements
that were consistent across the studies. With
input from both authors, the evidence was synthesized
and integrated into recommendations. Although
there is no specific focus on social inequalities, this
chapter examines cultural and gender differences in
intervention effects and also looks at both behavioral
and environmental interventions to find equitable and
sustainable solutions.
Interventions d uring p regnancy
Concerning prenatal factors, a recent review of risk
factors for overweight in preschool children found
strong evidence for a direct association between childhood
overweight and maternal pre - pregnancy body
size, maternal weight gain and smoking during
pregnancy. 8 On the matter of interventions, there are
currently four published studies on interventions to
24 – 27
prevent excessive weight gain during pregnancy
and more than 50 randomized controlled studies on
smoking cessation. 28 – 31 No studies evaluated the long -
term effect on weight status of young children.
Only one of the four studies on gestational weight
gain included birth weight as an outcome. Gray -
Donald et al 24 based their design on social learning
theory, compared 107 control subjects and 112 women
who received diet and activity intervention during
pregnancy in four Cree communities of James Bay,
Quebec. Intervention consisted of regular, individual
diet counseling, physical activity sessions and other
activities related to nutrition, but did not result in
differences in diet measured at 24 – 30 weeks ’ gestation,
and rate of weight gain over the second half of pregnancy
(0.53 ± 0.32 kg per week vs. 0.53 ± 0.27 kg
per week). Mean birth weights were also similar
(3741 ± 523 g vs. 3686 ± 686 g).
A Cochrane review of interventions promoting
smoking cessation published in 2004 shows that
smoking cessation programs in pregnancy were effective
at reducing the proportion of women who continued
to smoke, and also reducing low birth weight
and preterm birth. 31 No studies investigated the effect
on child obesity later in life.
Together, these studies demonstrate that pregnancy
is an important time for intervention. At present,
however, there are not enough studies to identify
effective interventions during pregnancy for preventing
obesity among infants and preschool children.
More interventions need to be implemented and
evaluated. Future studies should consider a multi -
component approach and have a longer - term follow -
up of child anthropometric outcome.
Interventions to
p romote b reastfeeding
Numerous interventions have been conducted to
promote breastfeeding. 32 However, only one cluster -
randomized trial of a breastfeeding promotion
examined the effect on child weight status beyond
infancy. From the total of 17,046 healthy breastfed
infants enrolled in the Promotion of Breastfeeding
Intervention Trial (PROBIT ) in the Republic of
Belarus, Kramer et al 33 followed 13,889 (81.5%) subjects
with measurements of anthropometric variables
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