Canadian children's and youth's pedometer-determined steps/day, parent-reported TV watching time, and overweight/obesity: the CANPLAY Surveillance Study.

BACKGROUND: This study examines associations between pedometer-determined steps/day and parent-reported child's Body Mass Index (BMI) and time typically spent watching television between school and dinner. METHODS: Young people (aged 5-19 years) were recruited through their parents by random digit dialling and mailed a data collection package. Information on height and weight and time spent watching television between school and dinner on a typical school day was collected from parents. In total, 5949 boys and 5709 girls reported daily steps. BMI was categorized as overweight or obese using Cole's cut points. Participants wore pedometers for 7 days and logged daily steps. The odds of being overweight and obese by steps/day and parent-reported time spent television watching were estimated using logistic regression for complex samples. RESULTS: Girls had a lower median steps/day (10682 versus 11059 for boys) and also a narrower variation in steps/day (interquartile range, 4410 versus 5309 for boys). 11% of children aged 5-19 years were classified as obese; 17% of boys and girls were overweight. Both boys and girls watched, on average, < 40 minutes of television between school and dinner on school days. Adjusting for child's age and sex and parental education, the odds of a child being obese decreased by 20% for every extra 3000 steps/day and increased by 21% for every 30 minutes of television watching. There was no association of being overweight with steps/day, however the odds of being overweight increased by 8% for every 30 minutes of additional time spent watching television between school and dinner on a typical school day. DISCUSSION: Television viewing is the more prominent factor in terms of predicting overweight, and it contributes to obesity, but steps/day attenuates the association between television viewing and obesity, and therefore can be considered protective against obesity. In addition to replacing opportunities for active alternative behaviours, exposure to television might also impact body weight by promoting excess energy intake. CONCLUSIONS: In this large nationally representative sample, pedometer-determined steps/day was associated with reduced odds of being obese (but not overweight) whereas each parent-reported hour spent watching television between school and dinner increased the odds of both overweight and obesity.

Markers of sedentarism: the joint Canada/U.S. Survey of health.

BACKGROUND: The Joint Canada/United States Survey of Health (JCUSH) was a one-time collaborative survey undertaken by Statistics Canada and the National Center for Health Statistics. METHODS: This analysis provides country-, sex-, and age-specific comparative markers of adult obesity and sedentarism, defined as independent and collective groupings of self-reported leisure-time inactivity (<1.5 MET-hours/day), usual occupational sitting, and no/low active transportation (<1 hour/week). Logistic regression assessed the likelihood of sedentarism in U.S. vs. Canada, with and without adjusting for BMI-defined obesity categories: healthy weight (18.5 ≤ BMI <25 kg/m2; n = 3542), overweight (25 ≤ BMI < 30 kg/m2; n = 2,651), and obesity (BMI ≥ 30 kg/m2; n = 1470). RESULTS: Compared with Canadians, U.S. adults are 24% more likely to be overweight/ obese, 59% more likely to be inactive in leisure-time, 19% more likely to report no/low active transportation, and 39% more likely to collectively report all sedentarism markers, adjusting for sex and age. Focusing on obese individuals in both countries, obese U.S. residents were 90% more likely to be inactive during leisure-time, 41% more likely to report no/low active transportation, and 73% more likely to report all sedentarism markers. CONCLUSIONS: This ecological analysis sheds light on differential risks of obesity and sedentarism in these neighboring countries.

Descriptive epidemiology of youth pedometer-determined physical activity: CANPLAY.

PURPOSE: Objective measurement with body worn instrumentation is a preferred and increasingly common way to gather information about young people's physical activity. Measured samples have been typically small and recruited through schools. The purpose of this article was to present the descriptive epidemiology of children and youth pedometer-determined physical activity on the basis of a large national sample. METHODS: Children and youth (19,789) were recruited through random digit dialing. Participants were asked to wear the pedometer for seven consecutive days and to log daily steps. Of the 58% of participants who returned pedometer data, 95% wore the pedometer for at least 5 d. Daily step counts below 1000 or above 30,000 steps were truncated accordingly, and all values were included in the descriptive analysis. RESULTS: Boys and girls aged 5-19 yr took 12,259 and 10,906 steps per day, respectively. Daily steps were higher among boys than girls and declined by age group in a pattern consistent with that predicted by other smaller samples internationally. Weekday steps per day were generally higher than weekend day steps per day and varied by season. CONCLUSIONS: This study demonstrates the viability of using relatively inexpensive pedometers and methods for the surveillance of young people's physical activity. The resulting descriptive data provide key information regarding the population distribution of pedometer-determined physical activity that may be useful for identifying target groups for population strategies and other interventions.