Activity, inactivity, and obesity: racial, ethnic, and age differences among schoolgirls.

Abstract

IntdudionAlthough studies have explored the frequency' and determinants2 of children's participation in physical activities, racial/ethnic and age differences (elementaly to high school) in activity levels have not been studied; also, the relationship between physical activity, sedentary behavior, and the prevalence of obesity in different racial/ethnic and age groups has not been examined. This study explored race-, ethnicity-, and age-related differences in activity, inactivity, and obesity among a multiracial sample of girls in grades 5 through 12 living in a low-tomedium income northeastem town. MeodsA school-based survey was administered from February through May 1991 to 552 girls residing in Lynn, Mass. The ethnic composition ofthe study population (64.3% White, 15.4% Black, 11.2% Hispanic, 4.3% Asian, and 4.7% other/mixed) was representative of the school district. Elementaiy schools (grades 5 and 6), junior high schools (grades 7 and 8), and high schools (grades 9 through 12) contnbuted 29.5%, 37.1%, and 33.3%, respectively, of the study population. After active parental consent was obtained and dropouts and absentees were excluded, the estimated response rate among students who were eligible to receive the questionnaire was 78%.Physical activity was self-reported on the Godin-Shepard Physical Activity Survey,3 which has good 2-week test-retest reliability and construct validity among children.4 The survey was modified by developing Height and weight were self-reported. Obesity was defined by age-and sex-appropriate reference data of body mass index (kg/i2) at the 85th percentile.5 Sedentary behavior or inactivitywas assessed by number of hours of television viewed per day; six closed-ended categories (ranging from less than 1 hour to 9.5 hours per day) were used in these assessments.Statistical Analysis Software6 was used in conducting statistical analyses. Age, race, and age-adjusted body mass index were controlled for in these analyses. Indicator variables were used for racial/ethnic and age groups, with White and high school as the referent groups.

Parent–child relationship of physical activity patterns and obesity

“…6,11,13,14 The association was, however, dependent on the assessment tool, because physical activity levels obtained from the prospective 3-day activity record were not related to overweight. Because the recording is based on subjective evaluation of the intensity of daily activities, an overestimation of activity intensity by overweight children could mask a true association between activity and obesity.…”

“…Several cross-sectional studies have shown a positive association between the time spent watching television and obesity in children, 4 ± 10 whereas other reports have failed to ®nd a relation. 11 ± 13 The association between children's vigorous or total physical activity and obesity is also inconsistent: some studies reported an inverse relation, 6,11,13,14 while some researchers did not ®nd an association. 7,9,10 The amount and kind of physical activity in children are modi®ed by physiological, biomechanical and social factors.…”

Relationships between media use, body fatness and physical activity in children and youth: a meta-analysis

“…A moderator analysis of the relationship between video/ computer game use and body fatness was not performed because second-order sampling error is likely to confound results when the initial number of effects is small. 7 TV viewing, video/computer game use and physical activity In total, 33 studies [11][12][13]17,18,21,25,[30][31][32]36,38,39,46,[48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65][66] were located that presented a measure of association between physical activity and TV viewing, playing video games or computer use. Nine studies were excluded from analyses either because they had serious design limitations, 46,50,51 presented insufficient data for meta-analytic synthesis, 11,12,54 presented data on composite measures of sedentary behavior 49,52 or reported on special populations.…”

“…Body fatness was usually assessed using skinfold thickness (60%) or BMI (37%) derived from direct observation of height and weight. Four samples 15,20,38 relied on self-reported height and weight to compute BMI. Only one sample used dualenergy X-ray absorptiometry (DXA), 35 which is considered a 'gold standard' technique for assessing fat mass in children.…”

Physical activity and sedentary behavior: a review of longitudinal studies of weight and adiposity in youth

“…89 Such null findings are also common. 40,57,90,91 We found two case-control studies in our review of the literature, which were essentially crosssectional in design. Television was significantly related to obesity in a case-control study of 223 obese 7-10-y-old children and controls in Sao Paulo.…”