Biology Reference
In-Depth Information
Ruiz, Castillo, and Sj¨ str¨m (2008)
further presented strong evidence to
support negative associations between PF, or to be specific, cardiorespiratory
fitness levels, and total body and abdominal adiposity in childhood and ado-
lescence. While all these of studies showed fairly consistent results, it should
be noted that there are various components of fitness measures and most of
the published studies used only a single fitness test to represent the fitness
component
(
Kim et al., 2005
). Moreover, due to the cross-sectional nature
of the study designs, the direction of causation between fitness and obesity
could not be clearly established.
Although energy intake and EE are known to be equally important in
maintaining energy balance, it is difficult to obtain accurate dietary intake
information from a young population. Therefore, the
FAO/WHO/
UNU (1985)
recommended that the estimate of EE in free-living individ-
uals be used for establishing the energy requirements in children and ado-
lescents
(
Wong, 1994
). However, EE can be influenced by many factors
and varies among age groups. The energy cost of activities may be greater
among children and adolescents compared to adults, and this difference
could be due to the smaller muscle mass, shorter legs, and greater propor-
tional amount of internal organs in these young populations (
Harrell
et al., 2005
)
. These factors may contribute to the higher total daily EE in
children and adolescents. Unfortunately, studies on the energy cost of daily
activities in children and adolescents worldwide are limited to a few activ-
ities. As a result, data from adults are often used as surrogates; hence, the
accuracy and validity of the estimates of energy requirements for children
and adolescents has often been questioned (
Ainsworth et al., 2000;
In comparison to the other countries, we found that there is currently no
research or literature that systematically examines the PA and fitness levels of
children and adolescents in the tropics. Moreover, data regarding the energy
costs of daily activities in these populations are scarce. Therefore, this review
aimed to report the PA, fitness levels, and energy costs of habitual activities per-
formed by children and adolescents and to extensively review the implications
of these components on the increasing prevalence of obesity in the tropics.
2. OVERWEIGHT AND OBESITY IN THE TROPICS
2.1. Overweight and obesity
In general, overweight and obesity can be defined as conditions of abnormal
or excessive fat accumulation that may impair health (
World Health
