321435_Print.indd

(やまだぃちぅ) #1

Overview of Correlates


The preceding data are largely derived from studies of children and adolescents in


economically better-off, developed countries. Information on correlates of activity


among youth from low- and middle-income countries is lacking (Bauman et al. 2012 ).


It would seemingly make sense to evaluate more detailed, though limited,field


studies in developing areas. For example, children and adolescents are essential to
household maintenance and subsistence strategies in Mesoamerican peasant commu-


nities. Moreover, when youth attend school, they are generally expected to contribute


to household maintenance and subsistence (Post 2001 ; Malina and Little 2008 ).


Specific household activities or chores of children and adolescents associated


with household subsistence have not received detailed consideration. Field obser-


vations in a rural indigenous subsistence agricultural community in southern


Mexico in 2000 provide some insights (Malina et al. 2008 ). Daily activities were


estimated among school children from a combination of questionnaires and inter-


views of school children. Although all children walked to and from school and the


majority participated in unorganized sport during free time, a significant portion of


daily physical activity occurred in the context of required household chores before


and after school and also on weekends. Household activities of girls tended to


cluster in light and moderate intensities, while those of boys tended to cluster in


moderate-to-vigorousand vigorous intensities. The distribution of activities and


activity intensities between boys and girls reflected the sex difference in division


labor in the rural community. Making tortillas, for example, is a constant in the life


of women, and girls learn the production skills early in life, while agricultural


chores are a constant in the life of men and boys. The household- and


agriculture-related activities of youth are essential components of the family routine


and labor supply. The daily activities for each youngster were converted to an


estimate of TEE using MET values for specific activities among children; resting


energy expenditure was predicted from height and weight. Estimated PAL was
1.89±0.13 in boys (n= 118, 12.2±2.2 years) and 1.79±0.16 in girls (n= 150,


12.1±2.1 years) (Malina, unpublished). The estimates were similar to those for


youth in rural areas of developing countries (Table5.2) and suggested, on average,


a moderately active lifestyle.


Similar observations were noted among rural Kenyan adolescents. In addition to


active transport to school, a good deal of their time was devoted to physically active


household chores, e.g., fetching and carrying water andfirewood, caring for and


herding cattle, and gardening, among others (Ojiambo et al. 2012 ). Estimated daily


MVPA (accelerometry) among rural Kenyan youth 10–17 years of age (14±1 years)


was quite high, 173±34 min/day in boys and 140±25 min/day in girls. In contrast,


estimated PALs based on DLW did not differ by sex, 2.2±0.5 in boys and 2.4±0.6 in


girls (Ojiambo et al. 2013 ), and indicated a very active lifestyle. The PALs exceed


those for youth in rural areas of developing countries (Table5.2).


88 R.M. Malina et al.

Free download pdf