Canadian journal of dietetic practice and research : a publication of Dietitians of Canada = Revue canadienne de la pratique et de la recherche en diététique : une publication des Diététistes du Canada, 2013
This national study was conducted to examine healthy eating programs, healthy eating education, a... more This national study was conducted to examine healthy eating programs, healthy eating education, and the food retail environments of schools. A total of 436 Canadian schools were studied. Administrators completed a questionnaire designed to assess school healthy eating programs, healthy eating education, and food retail environment. The number of chain fast food restaurants, chain cafés/coffee shops, and convenience stores within 1 km of schools was measured using geographic information systems food retailer measures from DMTI Spatial Inc. and the Yellow Pages. During the preceding year, 67% of schools had initiated healthy eating lunch programs while 18% had junk food-free days. The majority of schools offered cooking classes (59%) and healthy eating media literacy education (67%), while a minority offered gardening activities (15%) and field trips to farmers' markets (27%) and grocery stores (36%). Fifty-three percent had a school cafeteria, and most had a school tuck shop (75%...
The commonly held view that exercise alone is not a useful strategy for obesity reduction is draw... more The commonly held view that exercise alone is not a useful strategy for obesity reduction is drawn from studies with limitations that confound interpretation. Recent evidence counters the dogma that daily exercise produces only modest weight loss and suggests that exercise without diet restriction is an effective strategy for reducing obesity and related co-morbidities.
The purpose of this study was to determine skeletal muscle cutpoints for identifying elevated phy... more The purpose of this study was to determine skeletal muscle cutpoints for identifying elevated physical disability risk in older adults. Subjects included 4,449 older (≥60 years) participants from the Third National Health and Nutrition Examination Survey during 1988-1994. Physical disability was assessed by questionnaire, and bioimpedance was used to estimate skeletal muscle, which was normalized for height. Receiver operating characteristics
Because blood pressure (BP) tracks from childhood to adulthood, assessing levels in youth is rele... more Because blood pressure (BP) tracks from childhood to adulthood, assessing levels in youth is relevant. There are no recent BP data for Canadian children and adolescents, and past studies have used a variety of design and measurement devices. With a clinically validated oscillometric device, resting BP was measured in 2,079 respondents aged 6 to 19 years from the Canadian Health Measures Survey. The average of the last five of six BP measures taken one minute apart at a single visit was used in this report. Borderline or elevated BP was defined as greater than or equal to the 90th percentile of US reference values for participants aged 6 to 17 years. Borderline or elevated BP for 18- to 19-year-olds was defined as equal to or greater than 120 systolic BP or equal to or greater than 80 diastolic BP. Participants of any age who reported taking antihypertensive medication in the past month were also defined as having elevated BP. At ages 6 to 11 years, mean (standard error) systolic/dia...
The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and ... more The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and related comorbid conditions are not known. The effects of exercise without weight loss on fat distribution and other risk factors are also unclear. To determine the effects of equivalent diet- or exercise-induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat skeletal muscle mass, and insulin sensitivity in obese men. Randomized, controlled trial. University research center. 52 obese men (mean body mass index [+/-SD], 31.3 +/- 2.0 kg/m2) with a mean waist circumference of 110.1 +/- 5.8 cm. Participants were randomly assigned to one of four study groups (diet-induced weight loss, exercise-induced weight loss, exercise without weight loss, and control) and were observed for 3 months. Change in total, subcutaneous, and visceral fat; skeletal muscle mass; cardiovascular fitness; glucose tolerance and insulin sensitivity. Body weight decreased by 7.5 kg (8%) in both weight loss groups and did not change in the exercise without weight loss and control groups. Compared with controls, cardiovascular fitness (peak oxygen uptake) in the exercise groups improved by approximately 16% (P < 0.01). Although total fat decreased in both weight loss groups (P < 0.001), the average reduction was 1.3 kg (95% CI, 0.3 to 2.3 kg) greater in the exercise-induced weight loss group than in the diet-induced weight loss group (P = 0.03). Similar reductions in abdominal subcutaneous, visceral, and visceral fat-to-subcutaneous fat ratios were observed in the weight loss groups (P < 0.001). Abdominal and visceral fat also decreased in the exercise without weight loss group (P = 0.001). Plasma glucose and insulin values (fasting and oral glucose challenge) did not change in the treatment groups compared with controls (P = 0.10 for all comparisons). Average improvement in glucose disposal was similar in the diet-induced weight loss group (5.6 mg/kg skeletal muscle per minute) and in the exercise-induced weight loss group (7.2 mg/kg skeletal muscle per minute) (P > 0.2). However, these values were significantly greater than those in the control and exercise without weight loss groups (P < 0.001). Weight loss induced by increased daily physical activity without caloric restriction substantially reduces obesity (particularly abdominal obesity) and insulin resistance in men. Exercise without weight loss reduces abdominal fat and prevents further weight gain.
Applied physiology, nutrition, and metabolism = Physiologie appliquée, nutrition et métabolisme, 2014
The study objective was to estimate the proportion of excessive fast-food consumption by youth th... more The study objective was to estimate the proportion of excessive fast-food consumption by youth that is attributable to living and attending school in a neighbourhood with a moderate or high density of fast-food restaurants. This was a cross-sectional study of 6099 Canadian youths (aged 11-15 years) from 255 school neighbourhoods. All participants lived within 1 km of their school. The density of chain fast-food restaurants within a 1-km circular buffer surrounding each school was determined using geographic information systems. Excessive fast-food consumption (≥2 times per week) was assessed by questionnaire. Multilevel logistic regression analysis was used to examine associations. The population attributable risk estimates of excessive fast-food consumption due to neighbourhood exposure to fast-food restaurants were determined based on the prevalence of exposure and the results from the logistic regression. Eight percent of participants were excessive fast-food consumers. After adj...
To determine: 1) whether sarcopenic-obesity is a stronger predictor of cardiovascular disease (CV... more To determine: 1) whether sarcopenic-obesity is a stronger predictor of cardiovascular disease (CVD) than either sarcopenia or obesity alone in the elderly, and 2) whether muscle mass or muscular strength is a stronger marker of CVD risk. Prospective cohort study. Participants included 3366 community-dwelling older (>or= 65 years) men and women who were free of CVD at baseline. Waist circumference (WC), bioimpedance analysis, and grip strength were used to measure abdominal obesity, whole-body muscle mass, and muscular strength, respectively. Subjects were classified as normal, sarcopenic, obese, or sarcopenic-obese based on measures of WC and either muscle mass or strength. Participants were followed for 8 years for CVD development and proportional hazard regression models were used to compare risk estimates for CVD in the four groups after adjusting for age, sex, race, income, smoking, alcohol, and cognitive status. Compared with the normal group, CVD risk was not significantly ...
Although neighbourhood factors have been proposed as determinants of adolescent behaviour, few st... more Although neighbourhood factors have been proposed as determinants of adolescent behaviour, few studies document their relative etiological importance. We investigated the relationship between neighbourhood crime and cannabis use in a nationally representative sample of Canadian adolescents. Data from the 2009/10 Canadian Health Behaviour in School-aged Children (HBSC) survey (n=9134 14- and 15-year-olds) were combined with area-level data on crime and socioeconomic status of the neighbourhood surrounding the schools (n=218). Multilevel logistic regression analyses showed that after individual and contextual differences were held constant, neighbourhood crime related to cannabis use (OR 1.29, CI 1.12-1.47 per 1.0 SD increase in crime). This association was not moderated by parental support nor having cannabis-using friends. The amount of explained variance at the neighbourhood level was 19%. Neighbourhood crime is an important factor to consider when designing interventions aimed at ...
The body mass index (BMI) of youth often changes when they immigrate to a new country as a result... more The body mass index (BMI) of youth often changes when they immigrate to a new country as a result of the adoption of new behaviours, a process called acculturation. We investigated whether BMI differs by country of birth (Canada v. other countries) and ethnicity, both individually and together. We also examined whether time since immigration and health-related behaviour explain any observed BMI differences. Data sources were the Canadian Health Behaviour in School-Aged Children study and the Canada Census of Population. Participants were youth in grades 6-10 (weighted sample n = 19 272). A questionnaire was used to assess participants' sociodemographic characteristics, height, weight and health-related behaviour. We calculated BMIs from participants' self-reported heights and weights and used World Health Organization growth references to determine BMI percentiles. Based on self-reported heights and weights, BMI percentiles for foreign-born youth were lower than those of you...
The study objectives were to examine whether: 1) sedentary time is associated with sleep duration... more The study objectives were to examine whether: 1) sedentary time is associated with sleep duration, 2) sedentary time predicts the metabolic syndrome (MetS) independent of sleep duration and vice versa, and 3) sedentary time and sleep duration have an interactive effect on the MetS. This cross-sectional study is based on the 2003-2006 National Health and Nutrition Examination Survey. A sample of 1371 adults (aged ≥20 years) were studied. Average daily sedentary time and sleep duration were determined via 7-day accelerometry. Screen time was determined via questionnaire. The MetS was determined using standard criteria. Analysis of variance was used to examine relationships among sedentary time and screen time with sleep duration. Logistic regression was used to examine associations between sedentary time, screen time, and sleep duration with the MetS after controlling for several confounders. Sedentary time and screen time did not vary across sleep duration quartiles. Participants in ...
To provide descriptive information on the screen time levels of Mexican children. 5 660 children ... more To provide descriptive information on the screen time levels of Mexican children. 5 660 children aged 10-18 years from the 2012 National Health and Nutrition Survey (ENSANUT 2012) were studied. Screen time (watching television, movies, playing video games and using a computer) was self-reported. On average, children engaged in 3 hours/day of screen time, irrespective of gender and age. Screen time was higher in obese children, children from the northern and Federal District regions of the country, children living in urban areas, and children in the highest socioeconomic status and education categories. Approximately 33% of 10-14 year olds and 36% of 15-18 year olds met the screen time guideline of ≤ 2 hours/day. 10-18 year old Mexican children accumulate an average of 3 hours/day of screen time. Two thirds of Mexican children exceed the recommended maximal level of time for this activity.
Revista panamericana de salud pública = Pan American journal of public health, 2013
To determine the test-retest reliability and validity of the Spanish version of the short-form In... more To determine the test-retest reliability and validity of the Spanish version of the short-form International Physical Activity Questionnaire (IPAQ) among adults in Mexico. This was a cross-sectional study of a convenience sample of 267 adult factory workers in Mexico City. Participants were 19 - 68 years of age; 48% were female. Participants wore an accelerometer for 9 consecutive days and were administered the Spanish version of the short form IPAQ on two occasions (IPAQ1 and IPAQ2, separated by 9 days). The relation and differences between moderate-to-vigorous physical activity (MVPA) measures obtained from IPAQ1, IPAQ2, and the accelerometer were determined using correlations, linear regression, and paired t-tests. IPAQ1 and IPAQ2 measures of MVPA were significantly correlated to each other (r = 0.55, P < 0.01). However, MVPA was 44 ± 408 minutes/week lower in IPAQ1 than in IPAQ2, although this difference did not reach statistical significance (P = 0.08). The (min/week) measur...
Canadian journal of public health = Revue canadienne de santé publique
Obesity is a growing problem in Canada and worldwide. While obesity maps that convey changing rat... more Obesity is a growing problem in Canada and worldwide. While obesity maps that convey changing rates over time and geography provide a useful way to convey such information, regional obesity surveillance maps for Canada have not been published since 1998. This research provides a summary of changing Canadian obesity rates since that time. We computed estimated obesity rates for provinces and territories across Canada from 2000 to 2011. Data were based on Canadian Community Health Survey and corrected for self-report bias. Data reporting the estimated percent of the adult population who are obese were mapped over time overall and by sex according to Canadian province and territory. The data indicate that the estimated prevalence of obesity across Canada has continued to increase over the past 11 years. Current rates exceed 30% in the Maritime provinces (Newfoundland, New Brunswick, Nova Scotia, Prince Edward Island) and in two territories (Northwest Territory, Nunavut). Data for men a...
The accurate measurement of time devoted to physical activity, sedentary pursuits and sleep is di... more The accurate measurement of time devoted to physical activity, sedentary pursuits and sleep is difficult and varies considerably between surveys. This has implications for population surveillance and understanding how these variables relate to health. This sample of children (n = 878) was from the 2007 to 2009 Canadian Health Measures Survey. Moderate- to-vigorous physical activity (MVPA), sedentary behaviour and sleep duration were assessed using both a questionnaire and an accelerometer. This article compared parent-reported and directly measured physical activity, sedentary behaviour and sleep, and examined their associations, alone or in combination, with selected health markers in children aged 6 to 11. According to parent reports, the children in this study had an average of 105 minutes of MVPA, 2.5 hours of screen time and 9.7 hours of sleep per day; accelerometers recorded 63 minutes of MVPA, 7.6 hours of sedentary time and 10.1 hours of sleep per day. MVPA, measured by pare...
This article describes measures of abdominal obesity--waist circumference, waist-to-hip ratio, an... more This article describes measures of abdominal obesity--waist circumference, waist-to-hip ratio, and waist-to-height ratio--within body mass index (BMI) categories, using data from two population-based health surveys. Among normal-weight men, the percentages at increased/high health risk based on these three measures were not statistically different in 2007-2009 than in 1981. By contrast, among normal-weight women, increases were observed in the percentage at increased/high health risk based on each of the three measures. The percentage of overweight men at increased/high risk based on waist circumference rose from 49% in 1981 to 62% in 2007-2009, and among overweight women, the percentage at increased/high risk rose for each of the three measures (64% to 93% for waist circumference, 22% to 51% for waist-to-hip ratio, and 68% to 87% for waist-to-height ratio). Although substantial percentages of men and women in obese class I were at increased/high health risk based on abdominal obesi...
Urban sprawl is a potential environmental influence on youth overweight/obesity. However, little ... more Urban sprawl is a potential environmental influence on youth overweight/obesity. However, little is known about the association between urban sprawl and behaviours that influence obesity such as active transportation and physical activity. The study population consisted of 7,017 respondents aged 12 to 19 to the 2007/2008 Canadian Community Health Survey, living in Canada's 33 census metropolitan areas (CMAs). Factor analysis was used to obtain an urban sprawl score for each CMA, incorporating dwelling density, percentage of single or detached dwelling units, and percentage of the population living in the urban core. Multi-level logistic regression examined whether urban sprawl was associated with frequent active transportation (30 or more minutes a day), moderate-to-vigorous physical activity (MVPA) (60 or more minutes a day), and overweight/obesity. Urban sprawl was associated with active transportation among 12- to 15-year-olds, with the relative odds of engaging in at least 3...
Several organizations recommend the use of measures of abdominal obesity in conjunction with body... more Several organizations recommend the use of measures of abdominal obesity in conjunction with body mass index (BMI) to assess obesity-related health risk. Recent evidence suggests that waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) are increasing within BMI categories. This shift may have affected the usefulness of abdominal obesity measures. Data are from respondents aged 18 to 79 to the 2007 to 2009 Canadian Health Measures Survey. Using logistic regression, this paper examines cardiovascular disease (CVD) risk factors in relation to WC, WHR and WHtR within BMI health-risk categories. CVD risk factors considered include components of the metabolic syndrome. Among men in the normal and overweight BMI categories, WHR and WHtR were positively associated with having at least two CVD risk factors. All three abdominal obesity measures were associated with increased odds of having at least two CVD risk factors among normal-weight women. Abdominal obesi...
Objectives. To examine associations between obesity and occupational injury. Methods. Participant... more Objectives. To examine associations between obesity and occupational injury. Methods. Participants consisted of a representative sample of 7,678 adult Canadian workers. Participants were placed into normal weight, overweight, and obese categories based on their body mass index. Different injury types, location, and external causes were measured. Logistic regression was used to estimate relationships. Results. By comparison to normal weight workers, obese workers were more likely to report any occupational injuries (odds ratio (OR) 1.40, 95% confidence interval (CI): 0.98-1.99) and serious occupational injuries (1.49, 0.99-2.26). These relationships were more pronounced for sprains and strains (1.80, 1.04-3.11), injuries to the lower limbs (2.14, 1.12-4.11) or torso (2.36, 1.13-4.93), and injuries due to falls (2.10, 0.86-5.10) or overexertion (2.08, 0.96-4.50). Female workers, workers ≥40 years, and workers employed in sedentary occupations were particularly vulnerable. Increased ri...
Canadian journal of dietetic practice and research : a publication of Dietitians of Canada = Revue canadienne de la pratique et de la recherche en diététique : une publication des Diététistes du Canada, 2013
This national study was conducted to examine healthy eating programs, healthy eating education, a... more This national study was conducted to examine healthy eating programs, healthy eating education, and the food retail environments of schools. A total of 436 Canadian schools were studied. Administrators completed a questionnaire designed to assess school healthy eating programs, healthy eating education, and food retail environment. The number of chain fast food restaurants, chain cafés/coffee shops, and convenience stores within 1 km of schools was measured using geographic information systems food retailer measures from DMTI Spatial Inc. and the Yellow Pages. During the preceding year, 67% of schools had initiated healthy eating lunch programs while 18% had junk food-free days. The majority of schools offered cooking classes (59%) and healthy eating media literacy education (67%), while a minority offered gardening activities (15%) and field trips to farmers' markets (27%) and grocery stores (36%). Fifty-three percent had a school cafeteria, and most had a school tuck shop (75%...
The commonly held view that exercise alone is not a useful strategy for obesity reduction is draw... more The commonly held view that exercise alone is not a useful strategy for obesity reduction is drawn from studies with limitations that confound interpretation. Recent evidence counters the dogma that daily exercise produces only modest weight loss and suggests that exercise without diet restriction is an effective strategy for reducing obesity and related co-morbidities.
The purpose of this study was to determine skeletal muscle cutpoints for identifying elevated phy... more The purpose of this study was to determine skeletal muscle cutpoints for identifying elevated physical disability risk in older adults. Subjects included 4,449 older (≥60 years) participants from the Third National Health and Nutrition Examination Survey during 1988-1994. Physical disability was assessed by questionnaire, and bioimpedance was used to estimate skeletal muscle, which was normalized for height. Receiver operating characteristics
Because blood pressure (BP) tracks from childhood to adulthood, assessing levels in youth is rele... more Because blood pressure (BP) tracks from childhood to adulthood, assessing levels in youth is relevant. There are no recent BP data for Canadian children and adolescents, and past studies have used a variety of design and measurement devices. With a clinically validated oscillometric device, resting BP was measured in 2,079 respondents aged 6 to 19 years from the Canadian Health Measures Survey. The average of the last five of six BP measures taken one minute apart at a single visit was used in this report. Borderline or elevated BP was defined as greater than or equal to the 90th percentile of US reference values for participants aged 6 to 17 years. Borderline or elevated BP for 18- to 19-year-olds was defined as equal to or greater than 120 systolic BP or equal to or greater than 80 diastolic BP. Participants of any age who reported taking antihypertensive medication in the past month were also defined as having elevated BP. At ages 6 to 11 years, mean (standard error) systolic/dia...
The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and ... more The independent effects of diet- or exercise-induced weight loss on the reduction of obesity and related comorbid conditions are not known. The effects of exercise without weight loss on fat distribution and other risk factors are also unclear. To determine the effects of equivalent diet- or exercise-induced weight loss and exercise without weight loss on subcutaneous fat, visceral fat skeletal muscle mass, and insulin sensitivity in obese men. Randomized, controlled trial. University research center. 52 obese men (mean body mass index [+/-SD], 31.3 +/- 2.0 kg/m2) with a mean waist circumference of 110.1 +/- 5.8 cm. Participants were randomly assigned to one of four study groups (diet-induced weight loss, exercise-induced weight loss, exercise without weight loss, and control) and were observed for 3 months. Change in total, subcutaneous, and visceral fat; skeletal muscle mass; cardiovascular fitness; glucose tolerance and insulin sensitivity. Body weight decreased by 7.5 kg (8%) in both weight loss groups and did not change in the exercise without weight loss and control groups. Compared with controls, cardiovascular fitness (peak oxygen uptake) in the exercise groups improved by approximately 16% (P &lt; 0.01). Although total fat decreased in both weight loss groups (P &lt; 0.001), the average reduction was 1.3 kg (95% CI, 0.3 to 2.3 kg) greater in the exercise-induced weight loss group than in the diet-induced weight loss group (P = 0.03). Similar reductions in abdominal subcutaneous, visceral, and visceral fat-to-subcutaneous fat ratios were observed in the weight loss groups (P &lt; 0.001). Abdominal and visceral fat also decreased in the exercise without weight loss group (P = 0.001). Plasma glucose and insulin values (fasting and oral glucose challenge) did not change in the treatment groups compared with controls (P = 0.10 for all comparisons). Average improvement in glucose disposal was similar in the diet-induced weight loss group (5.6 mg/kg skeletal muscle per minute) and in the exercise-induced weight loss group (7.2 mg/kg skeletal muscle per minute) (P &gt; 0.2). However, these values were significantly greater than those in the control and exercise without weight loss groups (P &lt; 0.001). Weight loss induced by increased daily physical activity without caloric restriction substantially reduces obesity (particularly abdominal obesity) and insulin resistance in men. Exercise without weight loss reduces abdominal fat and prevents further weight gain.
Applied physiology, nutrition, and metabolism = Physiologie appliquée, nutrition et métabolisme, 2014
The study objective was to estimate the proportion of excessive fast-food consumption by youth th... more The study objective was to estimate the proportion of excessive fast-food consumption by youth that is attributable to living and attending school in a neighbourhood with a moderate or high density of fast-food restaurants. This was a cross-sectional study of 6099 Canadian youths (aged 11-15 years) from 255 school neighbourhoods. All participants lived within 1 km of their school. The density of chain fast-food restaurants within a 1-km circular buffer surrounding each school was determined using geographic information systems. Excessive fast-food consumption (≥2 times per week) was assessed by questionnaire. Multilevel logistic regression analysis was used to examine associations. The population attributable risk estimates of excessive fast-food consumption due to neighbourhood exposure to fast-food restaurants were determined based on the prevalence of exposure and the results from the logistic regression. Eight percent of participants were excessive fast-food consumers. After adj...
To determine: 1) whether sarcopenic-obesity is a stronger predictor of cardiovascular disease (CV... more To determine: 1) whether sarcopenic-obesity is a stronger predictor of cardiovascular disease (CVD) than either sarcopenia or obesity alone in the elderly, and 2) whether muscle mass or muscular strength is a stronger marker of CVD risk. Prospective cohort study. Participants included 3366 community-dwelling older (>or= 65 years) men and women who were free of CVD at baseline. Waist circumference (WC), bioimpedance analysis, and grip strength were used to measure abdominal obesity, whole-body muscle mass, and muscular strength, respectively. Subjects were classified as normal, sarcopenic, obese, or sarcopenic-obese based on measures of WC and either muscle mass or strength. Participants were followed for 8 years for CVD development and proportional hazard regression models were used to compare risk estimates for CVD in the four groups after adjusting for age, sex, race, income, smoking, alcohol, and cognitive status. Compared with the normal group, CVD risk was not significantly ...
Although neighbourhood factors have been proposed as determinants of adolescent behaviour, few st... more Although neighbourhood factors have been proposed as determinants of adolescent behaviour, few studies document their relative etiological importance. We investigated the relationship between neighbourhood crime and cannabis use in a nationally representative sample of Canadian adolescents. Data from the 2009/10 Canadian Health Behaviour in School-aged Children (HBSC) survey (n=9134 14- and 15-year-olds) were combined with area-level data on crime and socioeconomic status of the neighbourhood surrounding the schools (n=218). Multilevel logistic regression analyses showed that after individual and contextual differences were held constant, neighbourhood crime related to cannabis use (OR 1.29, CI 1.12-1.47 per 1.0 SD increase in crime). This association was not moderated by parental support nor having cannabis-using friends. The amount of explained variance at the neighbourhood level was 19%. Neighbourhood crime is an important factor to consider when designing interventions aimed at ...
The body mass index (BMI) of youth often changes when they immigrate to a new country as a result... more The body mass index (BMI) of youth often changes when they immigrate to a new country as a result of the adoption of new behaviours, a process called acculturation. We investigated whether BMI differs by country of birth (Canada v. other countries) and ethnicity, both individually and together. We also examined whether time since immigration and health-related behaviour explain any observed BMI differences. Data sources were the Canadian Health Behaviour in School-Aged Children study and the Canada Census of Population. Participants were youth in grades 6-10 (weighted sample n = 19 272). A questionnaire was used to assess participants' sociodemographic characteristics, height, weight and health-related behaviour. We calculated BMIs from participants' self-reported heights and weights and used World Health Organization growth references to determine BMI percentiles. Based on self-reported heights and weights, BMI percentiles for foreign-born youth were lower than those of you...
The study objectives were to examine whether: 1) sedentary time is associated with sleep duration... more The study objectives were to examine whether: 1) sedentary time is associated with sleep duration, 2) sedentary time predicts the metabolic syndrome (MetS) independent of sleep duration and vice versa, and 3) sedentary time and sleep duration have an interactive effect on the MetS. This cross-sectional study is based on the 2003-2006 National Health and Nutrition Examination Survey. A sample of 1371 adults (aged ≥20 years) were studied. Average daily sedentary time and sleep duration were determined via 7-day accelerometry. Screen time was determined via questionnaire. The MetS was determined using standard criteria. Analysis of variance was used to examine relationships among sedentary time and screen time with sleep duration. Logistic regression was used to examine associations between sedentary time, screen time, and sleep duration with the MetS after controlling for several confounders. Sedentary time and screen time did not vary across sleep duration quartiles. Participants in ...
To provide descriptive information on the screen time levels of Mexican children. 5 660 children ... more To provide descriptive information on the screen time levels of Mexican children. 5 660 children aged 10-18 years from the 2012 National Health and Nutrition Survey (ENSANUT 2012) were studied. Screen time (watching television, movies, playing video games and using a computer) was self-reported. On average, children engaged in 3 hours/day of screen time, irrespective of gender and age. Screen time was higher in obese children, children from the northern and Federal District regions of the country, children living in urban areas, and children in the highest socioeconomic status and education categories. Approximately 33% of 10-14 year olds and 36% of 15-18 year olds met the screen time guideline of ≤ 2 hours/day. 10-18 year old Mexican children accumulate an average of 3 hours/day of screen time. Two thirds of Mexican children exceed the recommended maximal level of time for this activity.
Revista panamericana de salud pública = Pan American journal of public health, 2013
To determine the test-retest reliability and validity of the Spanish version of the short-form In... more To determine the test-retest reliability and validity of the Spanish version of the short-form International Physical Activity Questionnaire (IPAQ) among adults in Mexico. This was a cross-sectional study of a convenience sample of 267 adult factory workers in Mexico City. Participants were 19 - 68 years of age; 48% were female. Participants wore an accelerometer for 9 consecutive days and were administered the Spanish version of the short form IPAQ on two occasions (IPAQ1 and IPAQ2, separated by 9 days). The relation and differences between moderate-to-vigorous physical activity (MVPA) measures obtained from IPAQ1, IPAQ2, and the accelerometer were determined using correlations, linear regression, and paired t-tests. IPAQ1 and IPAQ2 measures of MVPA were significantly correlated to each other (r = 0.55, P < 0.01). However, MVPA was 44 ± 408 minutes/week lower in IPAQ1 than in IPAQ2, although this difference did not reach statistical significance (P = 0.08). The (min/week) measur...
Canadian journal of public health = Revue canadienne de santé publique
Obesity is a growing problem in Canada and worldwide. While obesity maps that convey changing rat... more Obesity is a growing problem in Canada and worldwide. While obesity maps that convey changing rates over time and geography provide a useful way to convey such information, regional obesity surveillance maps for Canada have not been published since 1998. This research provides a summary of changing Canadian obesity rates since that time. We computed estimated obesity rates for provinces and territories across Canada from 2000 to 2011. Data were based on Canadian Community Health Survey and corrected for self-report bias. Data reporting the estimated percent of the adult population who are obese were mapped over time overall and by sex according to Canadian province and territory. The data indicate that the estimated prevalence of obesity across Canada has continued to increase over the past 11 years. Current rates exceed 30% in the Maritime provinces (Newfoundland, New Brunswick, Nova Scotia, Prince Edward Island) and in two territories (Northwest Territory, Nunavut). Data for men a...
The accurate measurement of time devoted to physical activity, sedentary pursuits and sleep is di... more The accurate measurement of time devoted to physical activity, sedentary pursuits and sleep is difficult and varies considerably between surveys. This has implications for population surveillance and understanding how these variables relate to health. This sample of children (n = 878) was from the 2007 to 2009 Canadian Health Measures Survey. Moderate- to-vigorous physical activity (MVPA), sedentary behaviour and sleep duration were assessed using both a questionnaire and an accelerometer. This article compared parent-reported and directly measured physical activity, sedentary behaviour and sleep, and examined their associations, alone or in combination, with selected health markers in children aged 6 to 11. According to parent reports, the children in this study had an average of 105 minutes of MVPA, 2.5 hours of screen time and 9.7 hours of sleep per day; accelerometers recorded 63 minutes of MVPA, 7.6 hours of sedentary time and 10.1 hours of sleep per day. MVPA, measured by pare...
This article describes measures of abdominal obesity--waist circumference, waist-to-hip ratio, an... more This article describes measures of abdominal obesity--waist circumference, waist-to-hip ratio, and waist-to-height ratio--within body mass index (BMI) categories, using data from two population-based health surveys. Among normal-weight men, the percentages at increased/high health risk based on these three measures were not statistically different in 2007-2009 than in 1981. By contrast, among normal-weight women, increases were observed in the percentage at increased/high health risk based on each of the three measures. The percentage of overweight men at increased/high risk based on waist circumference rose from 49% in 1981 to 62% in 2007-2009, and among overweight women, the percentage at increased/high risk rose for each of the three measures (64% to 93% for waist circumference, 22% to 51% for waist-to-hip ratio, and 68% to 87% for waist-to-height ratio). Although substantial percentages of men and women in obese class I were at increased/high health risk based on abdominal obesi...
Urban sprawl is a potential environmental influence on youth overweight/obesity. However, little ... more Urban sprawl is a potential environmental influence on youth overweight/obesity. However, little is known about the association between urban sprawl and behaviours that influence obesity such as active transportation and physical activity. The study population consisted of 7,017 respondents aged 12 to 19 to the 2007/2008 Canadian Community Health Survey, living in Canada's 33 census metropolitan areas (CMAs). Factor analysis was used to obtain an urban sprawl score for each CMA, incorporating dwelling density, percentage of single or detached dwelling units, and percentage of the population living in the urban core. Multi-level logistic regression examined whether urban sprawl was associated with frequent active transportation (30 or more minutes a day), moderate-to-vigorous physical activity (MVPA) (60 or more minutes a day), and overweight/obesity. Urban sprawl was associated with active transportation among 12- to 15-year-olds, with the relative odds of engaging in at least 3...
Several organizations recommend the use of measures of abdominal obesity in conjunction with body... more Several organizations recommend the use of measures of abdominal obesity in conjunction with body mass index (BMI) to assess obesity-related health risk. Recent evidence suggests that waist circumference (WC), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) are increasing within BMI categories. This shift may have affected the usefulness of abdominal obesity measures. Data are from respondents aged 18 to 79 to the 2007 to 2009 Canadian Health Measures Survey. Using logistic regression, this paper examines cardiovascular disease (CVD) risk factors in relation to WC, WHR and WHtR within BMI health-risk categories. CVD risk factors considered include components of the metabolic syndrome. Among men in the normal and overweight BMI categories, WHR and WHtR were positively associated with having at least two CVD risk factors. All three abdominal obesity measures were associated with increased odds of having at least two CVD risk factors among normal-weight women. Abdominal obesi...
Objectives. To examine associations between obesity and occupational injury. Methods. Participant... more Objectives. To examine associations between obesity and occupational injury. Methods. Participants consisted of a representative sample of 7,678 adult Canadian workers. Participants were placed into normal weight, overweight, and obese categories based on their body mass index. Different injury types, location, and external causes were measured. Logistic regression was used to estimate relationships. Results. By comparison to normal weight workers, obese workers were more likely to report any occupational injuries (odds ratio (OR) 1.40, 95% confidence interval (CI): 0.98-1.99) and serious occupational injuries (1.49, 0.99-2.26). These relationships were more pronounced for sprains and strains (1.80, 1.04-3.11), injuries to the lower limbs (2.14, 1.12-4.11) or torso (2.36, 1.13-4.93), and injuries due to falls (2.10, 0.86-5.10) or overexertion (2.08, 0.96-4.50). Female workers, workers ≥40 years, and workers employed in sedentary occupations were particularly vulnerable. Increased ri...
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Papers by Ian Janssen