Prevalence of and risk factors for childhood overweight and obesity

Abstract

CMAJ 2005;173(6):607-13 We measured standing height to the nearest 0.1 cm after students had removed their shoes and body weight to the nearest 0.1 kg on calibrated digital scales. Overweight and obesity were defined using the international body mass index cut-off points established for children and youth. 26 These cut-off points are based on healthrelated adult definitions of overweight (≥ 25 kg/m 2 ) and obesity (≥ 30 kg/m 2 ) but are adjusted to specific age and sex categories for children. 26The CLASS survey included a modified version of Harvard's Youth/Adolescent Food Frequency Questionnaire, 27 which gathers information on both dietary intake and habits pertaining to mealtime behaviours. It also included validated questions on the frequency of physical activities and the number of hours of sedentary activities (watching television, working on a computer, playing video games) taken from the National Longitudinal Survey of Children and Youth (NLSCY).28 Information on sociodemographic factors was taken from a survey completed by parents and included the child's sex, place of birth and residency, as well as the parents' marital status, income level and educational attainment. The children's ages were not included, since the vast majority of grade 5 students were either 10 or 11 years old at the time they completed the CLASS survey.We estimated neighbourhood income by averaging, per school, the postal-code level means of household income (available through the 2001 Canada census) of residential addresses of children attending that school. Finally, we developed and administered a short survey for school principals to collect information on school characteristics, including sales of soft drinks, presence of vending machines, type of food services, frequency of physical education classes and possible financial restraints for recreation and gymnasium equipment.Because our observations of students are nested within those of their schools, we assessed student and school-based factors at distinct levels using multilevel statistical methods. Specifically, student and parental factors were considered as first-level covariates. All school characteristics and neighbourhood income were considered as contextual factors and treated as second-level covariates. We first applied multilevel logistic regression methods to determine to what extent risk factors were associated with overweight or obesity. Second, we grouped each risk factor into 1 of 4 groups -dietary habits, activities, and sociodemographic and school-based factors -and then adjusted for all significant risk factors within each group. These estimates are referred to as theme-adjusted odds ratios. Third, we considered all significant risk factors simultaneously to quantify their independent importance for excess body weight.Because participation rates were slightly lower in residential areas with lower estimates of household income, we calculated re- †Theme-adjusted odds ratios are adjusted for lunch, family supper and supper in front of the television. ‡Fully...

Meal pattern and BMI in 9–11-year-old children in Finland

“…As in the present study, previous results on school lunch consumption relative to weight status have mostly shown no relationship (16)(17)(18)(19)(20) . Previous studies that focus only on dinner are lacking.…”

Determinants of childhood overweight and obesity in China

“…§ For details of subjects, see p. 211. Benton, 2004;Veugelers & Fitzgerald, 2005), concluding that parental overweight is the most potent risk factor for childhood obesity. Treuth and colleagues found that a stepwise increase in gains in fat mass and percentage body fat over time occurred with increasing parental body weight status (Treuth et al 2003).…”

“…Parents may be responsible for the overconsumption of cooking oil by children. Parents' socioeconomic status also has an important effect on childhood obesity (Veugelers & Fitzgerald, 2005). Being nationally representative and comprising both diet and physical activity information and parental information are strengths of the present study.…”

Effect of joint physical activity on the physical condition of parents and children

“…Activities based on aerobic exercise have a greater benefit to the general health of children, other than bone health which requires higher-impact physical activities (Veugelers, & Fitzgerald, 2005).…”