Biology Reference
In-Depth Information
energy in obese compared to normal weight children and adolescents. Thus,
PA interventions should incorporate these types of activities to assist children
and adolescents in body weight reduction.
Differences in the energy cost of PA associated with obesity are still
largely unknown (
Hill & Saris, 1998
)
, although as obesity develops, the
energy cost of weight-bearing PA increases (
Miller & Blyth, 1955;
Passmore, 1956
). The degree of adiposity (
Murray et al., 1993
) and total
body mass (
Peyrot et al., 2010
)
have been shown to be determinants of
the energy cost of weight-bearing activities, such as walking and running.
Peyrot et al. (2010)
reported that the energy cost of walking was reduced
in weight-reduced adolescents because less leg muscles were required.
However,
Beatriz and Oded (2003)
found that adiposity was not associated
with the energy cost of locomotion. On the other hand, laboratory studies
show that fatness and the energy costs of specific activities are similar in lean
and obese children after adjusting for differences in body composition
In summary, based on available evidence, walking at a high speed and run-
ning could be used in exercise modules to help promote weight loss. How-
ever, the duration and intensity of the PA are more important than the energy
cost of specific activities for reducing body weight. A major limitation of a
majority of the studies examining the role of the energy costs of activities
and EE in the etiology of obesity was their cross-sectional design, in which
causal relationships could not be determined. Nevertheless, since studies on
the energy costs of habitual activities and the implication of these factors
on obesity are scarce, more studies are recommended. Knowledge regarding
the energy cost of physical activities is essential for planning PA programs to be
used inmanaging and treating children and adolescents with weight problems.
7. CONCLUSION
In conclusion, the prevalence of overweight and obesity as well as
sedentary behavior is increasing, while PF levels in children and adolescents
are declining in the tropics. These findings indicate a potential threat to the
future health of this population. The role of PA or PF in predicting
overweight or obesity remains inconclusive in the tropics, mostly due to
the limitations related to methodological designs. More longitudinal studies
and further prospective studies are needed to determine the cause and effect
and the types of the relationships among PA, PF, and obesity. In particular,
studies that investigated the energy cost of activity and overweight/obesity
