|Childhood obesity is arguably the most significant global public
health threat, yet effective strategies to contain or prevent the
disease are not available. This review examines the physical activity
patterns of children and the role physical activity plays in daily
energy expenditure. The prevailing focus on moderate to vigorous activity
in childhood means there is limited objective information on either
sedentary behaviour or non-exercise activity thermogenesis (NEAT),
the energy expended during the activities of daily living. Most strategies
targeting the prevention of childhood obesity have focused upon adding
moderate to vigorous activity and have not been particularly successful.
The low efficacy of more purposeful activity is perhaps not surprising
because of the small variance in children's physical activity levels
explained by moderate to vigorous activity. Subtle changes in NEAT
have in contrast been shown to account for differences in fat-mass
gain or resistance in adults. Theoretically, manipulating a child's
living environment to enhance NEAT would create a positive gain in
TDEE, a gain that could lead to the prevention of excess fat-mass.
More careful consideration of the specific aspects of physical activity
that are most influential in the maintenance of body weight in childhood
is a priority. Appreciating the role NEAT may play in the variation
of total daily energy expenditure in children is a future challenge
for physical activity research.
WORDS: Physical activity, energy expenditure, obesity, children.