Obesity Rates Among Rural Ontario Schoolchildren Tracey Galloway, BScN, MA, PhD Candidate
ABSTRACT Background: The majority of existing studies of obesity risk among Canadian children come from urban populations. The purpose of this study is to assess the prevalence of obesity in a sample of rural Ontario children. Methods: Measures of height and weight were obtained for 504 children attending seven public elementary schools in Grey and Bruce Counties, a predominantly rural area of Southern Ontario. Body mass index (BMI, or weight/height²) scores were calculated and compared with reference data from the Centers for Disease Control.1 Results: Rates of overweight and obesity were high in this sample, with 17.7% of children classified as overweight and 10.9% classified as obese. There was a significantly high prevalence of overweight for both boys (17.8%) and girls (17.5%) (Chi-square=75.70, p0.05). Conclusion: Findings indicate that among rural children – particularly boys – risk of overweight and obesity are at least as high as in their urban Canadian counterparts. There appear to be fewer girls than boys at the extreme high end of the distribution of BMI, which may indicate differences in the growth environment of rural boys and girls. MeSH terms: Child; obesity; overweight; body mass index; child health; rural health
he attention of North American public health researchers is increasingly focussed on the prevalence of obesity and its comorbidities, such as type 2 diabetes and cardiovascular disease. 2-4 Canadian data on obesity prevalence reflects the larger North American trend toward high rates of adult obesity and a rapidly increasing population of overweight children. It is to be expected that across such a large nation, Canadian communities will exhibit a diverse range of obesity prevalence, mitigated by various local forces. Researchers have documented negative associations between childhood obesity and numerous socio-economic factors, among them income, parental employment status, and parental educational attainment. 5-12 In addition, there is an emerging body of research describing neighbourhood-level effects of place on obesity risk.10,13,14 In an analysis of Canadian childhood obesity rates by both geographic and socioeconomic variables, Willms et al.15 demonstrate that geography (in this case, province of residence) has a significant association with obesity prevalence that is both greater than and separate from the effect of socio-economic variables such as family income or parental educational attainment. It would appear, then, that area-level factors may play a significant role in the development of childhood obesity. This relationship between neighbourhood and child growth and nutrition has been explored in urban Canadian communities.10,11 While Canadian researchers stress the need for directly measured data at the national and local level, 16,17 few studies (Crooks et al.,6 for example) target rural communities specifically. The purpose of this study is to assess the growth and nutrition of children living in a geographically rural area of Canada. This paper reports findings from the anthropometry portion of data collection.
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METHODS La traduction du résumé se trouve à la fin de l’article. Correspondence: Tracey Galloway, Health Sciences Program, University of Northern British Columbia, 3333 University Way, Prince George, BC, V2N 4Z9, Tel: 250-960-5363, E-mail:
[email protected] Sources of funding: This research is funded by a grant from the McMaster University School of Graduate Studies. The author is supported by a Doctoral Fellowship from the Social Sciences and Humanities Research Council of Canada. SEPTEMBER – OCTOBER 2006
The Bluewater Nutrition Project is a study of children’s growth and nutrition in rural Ontario, Canada. Between January and June 2004, anthropometry, 24-hour dietary recalls, and focus groups were conducted with children. The sample was conCANADIAN JOURNAL OF PUBLIC HEALTH 353
OBESITY RATES AMONG RURAL ONTARIO SCHOOLCHILDREN
structed from the populations of seven elementary schools in the Bluewater District School Board, located in the Georgian Bay region of Southern Ontario. The schools serve a diverse range of community sizes: the smallest school communities are entirely rural, with all children bused from surrounding townships; the largest school is located in a small city, population 21,000. All school communities fall under the Statistics Canada definition of “rural nonmetropolitan”.18,19 Ethics approval for this study was obtained from the McMaster Research Ethics Board, McMaster University, as well as from the Bluewater District School Board and the Grey Bruce Health Unit. Letters of information were distributed to 1,042 students in grades 2-8; the guardians of 535 children returned written consent for children’s participation in the study (51.3% participation rate). Verbal assent was elicited from children at the time of measurement. Two children declined to be measured and were excluded from the sample. In addition, a number of children were absent from school on the day of measurement. Anthropometric measures were conducted on a total of 504 children (253 boys and 251 girls) ages 7-14 years. All measurements were performed by the author in private rooms on school premises, with a research assistant present to record data. Children were asked to remove their shoes. Height was measured with a portable stadiometer (Perspective Enterprises PE-AIM-101). Weight was measured with a portable digital scale (Tanita TBF-551). Measurement techniques were consistent with Lohman et al.’s20 standardized procedures for anthropometric measures. In order to test for intra-observer error, 57 of the 504 children were randomly selected and measured a second time. Technical error of measurement (TEM) and coefficient of variation (CV) were within acceptable limits for both height (TEM=0.263; CV=0.183) 21 and weight (TEM=0.116; CV=0.300).22 Coefficient of reliability (R) for both variables was 0.999. Anthropometric measures were converted to Z-scores and percentiles using Epiinfo Version 3.3, and analyzed using SPSS Version 12.0 software. Students T-tests were conducted on mean Z scores to permit comparison with the 2000 CDC 354 REVUE CANADIENNE DE SANTÉ PUBLIQUE
TABLE I Mean BMIZ Scores Age (Years) 7 8 9 10 11 12 Total
n 26 40 29 68 56 23 242
Boys Mean BMIZ 0.86 0.62 0.53 0.71 0.42 0.31 0.54
St. Dev. 0.89 0.98 1.05 0.93 0.98 1.09 1.00
n 15 29 51 53 53 29 245
Girls Mean BMIZ 0.49 0.3 0.59 0.36 0.25 0.31 0.39
St. Dev. 0.52 0.96 0.85 0.88 0.98 0.73 0.86
TABLE II ≥85 and
