in its management. For each obese child and adolescent different factors contribute
to the development of his or her obesity. The main aim of dietary treatment
is to add to energy balance and thus to achieve healthy body weight at normal
growth and development. Maintenance of healthy weight is brought about by
balanced energy intake and energy expenditure. In this chapter we:
• discuss the eating habits of obese and nonobese children,
• give nutritional guidelines for children and adolescents,
• propose methods to realize these guidelines in daily practice.
Eating Habits of Obese and Nonobese Children
Dietary records have been used to examine the relationship between nutrition
and adiposity. Measurements of dietary intake are difficult and different
assessment methods may lead to different results in individual subjects [1]. In
several studies energy intake and expenditure data seemed incompatible [2–16].
Underreporting introduced a considerable and unacceptable error in the estimate
of energy intake. Dietary underreporting has been described in obese subjects
[2–6, 8, 16]. In conclusion underreporting increase with excess body weight. In
addition, psychological aspects of eating behavior were associated with underreporting
and may have had an influence. A high cognitive restraint and a high
level of disinhibition were both associated with severe underreporting [17].
These biases probably affected the results of many studies. The limitation of
dietary surveys, particularly underreporting by obese subjects, have been widely
discussed [2–8, 17]. Even if there are some errors in reported intakes, consistent
tendencies do emerge from diverse studies.
Most people believe that obese and overweight children have a higher energy
and fat intake than normal-weight children. However, no clear-cut associations
were found in nutrient and/or food intake and body weight of German children
aged 5–7 years. Health and body weight-related quality of food intake (as
reflected by the mean dietary pattern index) did not differ between overweight
and normal weight children [18, 19]. In addition the distribution of the dietary
pattern index is very narrow, i.e. the 10th percentile of score is 24 points and the
90th percentile of score is 37 points of a total of 52 points. These results show that
food choices are very similar and independent of the body size of children [20].
Thus, a clear association between overweight and dietary pattern is unlikely to
exist. These data are in accordance with measurements on British children aged
1.5–4.5 years where no association was found between diet and body size [21].
The association between dietary fat and overweight has been questioned.
Epidemiological data do not consistently show an association between fat intake
and overweight in children and adolescents [22, 23]. In a group of 6-year-old
French children there was also no relationship between sucrose intake and BMI
[24]. By contrast, in a cross-sectional study in US school-age children Harnack
et al. [25] found 10% greater energy intake in children who consumed sugarsweetened
soft drinks than in those who did not. Additionally, the results of a
prospective observational study indicate a 60% increased risk of development
of overweight in middle-school children for every daily serving, after controlling
for the effects of confounding factors [26]. Sugar-sweetened soft drinks might
promote energy intake and excessive weight gain because of their high glycemic
index [27].
In the Muscatine Risk Factors Survey it was found that obese children consumed
significantly more energy per day than their nonobese peers but this association
became negative when energy was expressed as kJ/kg body weight [28].
Valoski and Epstein [29] also found no significant differences in the caloric and
fat content of the diets eaten by obese and nonobese children aged 8–12 years.
However, in this study obese children consumed more protein. In another study on
Spanish normal-weight and obese children and adolescents there were no betweengroup
differences with respect to energy intake. But obese adolescents derived a
greater proportion of their energy from protein and fat and less from carbohydrate
[30]. In a study of French children aged 7–12 years, a high percentage of protein
in diet was positively associated with BMI as well as subscapular skinfold thickness
[31]. There were no associations between energy or fat content of diet and
body size or fat mass. Even more confusing, Spyckerelle et al. [32] found a negative
association between BMI and energy intake but positive association between
BMI and percentage of energy derived from protein in French adolescents.
Contrary to these data an analysis of nutrient intake in 9- to 10-year-old
children showed that body fatness was positively associated with fat and protein
but had a negative correlation with CHO intake after controlling for gender and
energy intake [33]. In addition, obese children of obese parents enjoy fatty
foods and eat them in large quantities [34, 35]. High fat intake predicted
adiposity in children in two other studies [28, 36].
Besides quantitative food intake the food choice as well as meal patterns
are other important risks for childhood overweight. Several studies reported differences
in circadian distribution of food intake between obese and nonobese
adults and children. Breakfast of obese subjects added less of daily energy intake
than breakfast of nonobese subjects [37, 38]. By contrast, obese children had
dinner with higher energy content when compared to normal-weight controls
[37, 38]. Other studies showed an inverse relationship between number of daily
meals and body adiposity. For example, three meals per day resulted in higher
risk to become obese than five or seven meals per day irrespective of energy
intake [39, 40]. Five or seven meals a day doesn’t mean snacking. Extraprandial
eating is practiced by both obese and nonobese subjects [41]. In a field study,
it is difficult to assess how snacking and nibbling contribute to energy intake,
because underreporting or selective reporting is a frequent observation significantly
affecting between-meal eating [42].
Other eating habits show that excessive energy intakes during binges create
a positive balance of energy. In obesity, no corrective behaviors such as purging
or self-induced vomiting take place in contrast to bulimia nervosa. Some obese
subjects report binges with rapid ingestion of large amounts of food accompanied
with feelings of loss of control [43]. In addition, obese subjects have a
tendency to eat faster than their lean controls [44].
In summary, all children and adolescents, i.e. overweight as well as normalweight,
prefer so-called ‘unhealthy’ food choices (e.g. fast food). However,
there is no clear association between food or nutrient intake and overweight.
Although the relation between dietary fat and overweight has been questioned,
a high fat intake is a considerable aspect in the development of overweight and
obesity, because fat is the most energy dense macronutrient. In addition, there
is some evidence that a low CHO and thus a high fat intake promoted adiposity
in children. The impacts of other items or rather risks of overweight, e.g.
portion size, meal frequency, psychological aspects, are not well referenced in
children and adolescents.
0 komentar:
Posting Komentar