Preventing Childhood Obesity - Evidence Policy and Practice.pdf

Developing country perspectives on obesity prevention policies and practices
families may be able to cope with their food bills for
one week, but are unsure of what will happen the following
week as they are not able to build up food
reserves. In practice, the lesson is that they eat as much
as they can since they do not know when they will fall
below the food sufficiency line. 20,21
Household food insecurity is defined as limited or
uncertain availability of nutritionally adequate and
safe foods, and limited or uncertain ability to acquire
acceptable foods in socially acceptable ways. 18,22 The
possible paradoxical association of hunger and food
insecurity with childhood obesity was first raised in a
case report in 1995. 23 The author speculated that this
association may be because of “ an adaptive process
to food shortages whereby increasing the consumption
of inexpensive energy dense foods results in
increasing body mass ”. Plausible mechanisms that
may explain this association include cheaper cost and
over-consumption of energy-dense foods, overeating
when foods become available, metabolic changes that
may permit more efficient use of energy, fear of food
restriction, and higher susceptibility to hunger, disinhibition
and environmental cues. 24,25
Socio - economic disadvantage in childhood is positively
associated with an increased risk of obesity in
adulthood. Lissau and Sorensen 26 showed that
9 –10-year-old children in Copenhagen rated as dirty
and neglected by school personnel were 9.8 times
more likely to be obese 10 years later. Olson et al
in 2007 27 attempted to explain why food insecurity
as it is experienced in rich countries such as the
USA results in adult obesity. After following 30
rural women with at least one child, their most important
conclusion was that growing up in a poor
household appeared to “ super - motivate some women
to actively avoid food insecurity in adulthood by
using food to meet emotional needs after deprivation
”. As the authors point out, this behaviour towards
food may be a possible mechanism for explaining the
association between childhood poverty and adult
obesity.
Drewnowski, in 2007, 28 demonstrated that much of
the past epidemiologic research is consistent with a
single parsimonious explanation: obesity has been
linked repeatedly to consumption of low - cost foods.
Refined grains, added sugars, and added fats are inexpensive,
tasty and convenient. The fact that energy -
dense foods cost less per megajoule than nutrient - dense
foods, means that energy - dense diets provide not only
cheaper energy, but may be preferentially selected
by the lower - income consumer. In other words,
the low cost of dietary energy (dollars/megajoule),
rather than specific food, beverage, or macronutrient
choices, may be an important predictor of weight gain
amongst poorer populations.
In examining the childhood obesity epidemic from
the perspective of economics, Cawley 29 reports that
the market has contributed to the recent increase
in childhood overweight in three main ways. First,
the real price of food fell, particularly energy - dense
foods; second, rising wages increased the “ opportunity
costs ” of food preparation for people in the workforce,
encouraging them to spend less time preparing
meals; and third, technological changes created incentives
to use prepackaged food rather than to prepare
foods.
Several economic rationales justify government
intervention in markets to address these problems.
First, because free markets generally under - provide
information, governments may intervene to provide
consumers with nutrition information they need.
Second, because society bears the soaring costs of
obesity, the government may intervene to lower the
costs to taxpayers. Third, because children are not
what economists call “ rational consumers ”— they
cannot evaluate information critically and weigh the
future consequences of their actions — the government
may step in to help them make better choices.
The government could disseminate information to
consumers directly, it could protect children from the
marketing of unhealthy foods and could also apply
taxes and subsidies that discourage the consumption
of these or encourage physical activity. It could also
require schools to remove vending machines for soft
drinks and candy. From the economic perspective,
policy - makers should evaluate these options on the
basis of cost – effectiveness studies.
Until recently, it was commonly thought that nutrition
- related chronic diseases were associated with
wealthy societies, but it has been shown in almost all
categories of developing countries that nutrition
imbalances are most frequent among the poor. 30 This
is especially evident in migrant populations; for
example, in northern Mexico, there has been a dramatic
increase in obesity and diabetes among indigenous
populations who have become progressively
287