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Conventional wisdom holds that natural patterns of intake among
young children are erratic, where children eat "like birds"
one day and "like horses" the next. Research provides
evidence to the contrary. Fomon and colleagues demonstrated that
infants could self-regulate energy intake-consuming consistent energy
from formula over the course of a 24-hour period-when formula energy
density and/or energy source (carbohydrate or fat) were modified
.
Early work from the 1920s revealed that young children eat to energy
needs when offered a variety of nutritious foods in a non-controlling
fashion . Subsequent research has
indicated that preschool-aged children also have the ability to
respond to energy density cues within a meal and to adjust their
food intake in relation to energy density. Using single meal protocols
in which a preload and a main course are offered, Birch and colleagues
have consistently demonstrated that children consume less during
a meal after ingesting high energy preloads than after low energy
preloads. As shown in Figure 3,
children exhibited a greater responsiveness to the energy content
of the foods consumed than did their mothers who consumed roughly
the same amount of food at lunch whether given a low or high energy
preload. (Birch & Deysher, 1986).
| Figure 3. Children's and
mothers' energy intake at lunch (after the ingestion of high
and low calorie "preloads" or snacks). Children adjust
energy intake to reflect the energy content of the preload.
In contrast, mothers showed little evidence of compensation. |
The ability to self-regulate energy intake has been documented
in young children for both carbohydrate- and fat-derived sources
of energy . Also, self-regulation
of energy intake appears to be maintained through at least the prepubertal
years and is evident in at least
some adults .
Children's energy intake over the course of 24-hour periods has
also been examined. As shown in Figure 4, while children's intake
at meals is considerably variable, total daily energy intake is
relatively tightly regulated .
| Figure 4. The variability
in young children's energy intake at individual meals is quite
high. However, collapsed over a 24-hour period, children's energy
intake is relatively consistent. |
These data provide evidence that preschool-aged children can adequately
self-regulate energy intake, at least as displayed under laboratory
settings.
Reinforcing Children's Ability to Self-Regulate
Energy Intake
Individual differences in the extent to which children self-regulate
energy intake clearly exist and are systematically related to differences
in children's weight and adiposity; preschool-aged children who
show less evidence of self-regulating energy intake tend to be heavier
. These differences in body
habitus are certainly attributable, in part, to genetic inheritance.
However, the gene-environment interaction is also a powerful contributor
to children's weight outcome.
| "... suggest that children can be taught
to focus on hunger and satiety cues and consequently can improve
their ability to self-regulate energy intake." |
The findings of a recent intervention suggest that
children can be taught to focus on hunger and satiety cues and consequently
can improve their ability to self-regulate energy intake .
Preschoolers were studied in their normal childcare environment
and were measured at baseline for their ability to self-regulate energy
intake. To capture self-regulation ability, children's food intake
was measured on two separate days at two lunches, which differed only
in terms of the energy content of a drink consumed 20 minutes prior
to the meal. The drink came in two versions: a noncaloric "juice
drink" sweetened with aspartame (3 kcal/serving) or a relatively
energy-dense version that contained sucrose and starch (150 kcal/serving).
On one occasion, children consumed the low energy drink and then,
after 20 minutes, a main meal that consisted of foods which children
know and like. On another day, children consumed the high energy preload
and were again given the opportunity to eat the same lunch meal. Evidence
of self-regulation was exhibited if children consumed less energy
at lunch following the high energy preload than after the low energy
preload.
The degree of accuracy that children show in self-regulation is
captured by a "Compensation Index" (COMPX) that reflects
the percent adjustment that children show in their lunchtime intake.
A COMPX score of 100% reflects "perfect," or calorie-for-calorie
self-regulation. A negative COMPX score occurs when children consume
more energy from lunch following the high energy preload.
| Figure 5. Children who
over-and under-regulated energy intake at a lunch showed improved
self-regulation of energy intake post-intervention. |
Initially, the children's mean COMPX was low with a high degree
of variability in self-regulation ability. Subsequent to a 6-week
intervention period, during which children were engaged in role-play
to help them identify and utilize internal cues of hunger and satiety
to guide their eating, children showed significant improvement in
self-regulation of energy intake (COMPX scores). As Figure 5 illustrates,
after the intervention there were both fewer children who under-ate
or over-ate when observed at a lunch meal. These findings highlight
that children's ability to self-regulate energy intake can be modified
by the environment in which eating occurs. Further, these data support
the notion that attentiveness to internal cues may play a positive
role in the attainment of healthy eating behaviors and weight.
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