Association of physical activity and sitting time with tobacco and alcohol use in 222,495 adolescents from 66 countries.

BACKGROUND: The prevalence of tobacco and alcohol use among adolescents is alarming, and these substances are among the leading risk factors for current and future health among adolescents. Physical activity has the potential to help prevent substance use among adolescents. The objective of this study was to evaluate the association between physical activity, modes of transportation to or from school, and sitting time with tobacco and alcohol use among 222,495 adolescents. METHODS: This cross-sectional study used data from national surveys conducted in 66 countries, obtained through the Global School-based Student Health Survey, and included adolescents aged 11 to 17 years. Information on physical activity, transportation to or from school, sitting time, and tobacco and alcohol use was collected through self-report questionnaires. Generalized linear models were employed to estimate the associations between these variables. RESULTS: The analysis, adjusted for sex, age, and region, revealed that being physically active was associated with lower odds of smoking (OR: 0.86, 95%CI: 0.83-0.89), alcohol use (OR: 0.74, 95%CI: 0.72-0.76), binge drinking (OR: 0.66, 95%CI: 0.62-0.69), and drunkenness (OR: 0.85, 95%CI: 0.83-0.88) compared to inactivity. Insufficiently active participants also had lower odds of tobacco use (OR: 0.83, 95%CI: 0.80-0.85), alcohol use (OR: 0.77, 95%CI: 0.75-0.79), binge drinking (OR: 0.91, 95%CI: 0.87-0.96), and drunkenness (OR: 0.88, 95%CI: 0.85-0.90) compared to inactive participants. Additionally, active transportation to or from school was associated with lower odds of tobacco use (OR: 0.97, 95%CI: 0.95-0.99), alcohol use (OR: 0.94, 95%CI: 0.92-0.96), and binge drinking (OR: 0.78, 95%CI: 0.75-0.81) compared to those using passive transportation. Participants with acceptable sitting time, however, were more likely to use tobacco (OR: 1.48, 95%CI: 1.45-1.52), use alcohol (OR: 1.68, 95%CI: 1.64-1.72), binge drink (OR: 1.68, 95%CI: 1.62-1.75), and experience drunkenness (OR: 1.66, 95%CI: 1.62-1.69) compared to those with excessive sitting time. CONCLUSION: Being physically active, even at insufficient levels, may have beneficial effects on tobacco and alcohol use in adolescents. Acceptable sedentary time, on the other hand, was positively associated with tobacco and alcohol use.

Joint Association between Sedentary Time and Moderate-to-Vigorous Physical Activity with Obesity Risk in Adults from Latin America.

Recent studies have shown various relationships between physical activity and the incidence of obesity, but this study critically explored the association of sedentary time (ST) and moderate-to-vigorous physical activity (MVPA) with obesity risk in adults from eight Latin American countries. ST and MVPA were assessed with accelerometers and stratified into 16 joint categories. Multivariate logistic regression models were used. The obesity risk indicators evaluated were body mass index (BMI), waist circumference (WC), and neck circumference (NC). Quartile 4 of ST and ≥300 min/week of MVPA was associated with lower odds of BMI compared to quartile 1 of ST and ≥300 min/week of MVPA. Quartile 1 of ST and 150-299 min/week of MVPA, quartile 1 of ST and 76-149 min/week MVPA, quartile 3 of ST and 76-149 min/week MVPA, and quartiles 1, 2, and 3 of ST with 0-74 min/week MVPA were associated with higher odds of high WC compared to quartile 1 of ST and ≥300 min/week of MVPA. Quartile 3 of ST and 150-299 min/week of MVPA, quartiles 1 and 3 of ST and 76-149 min/week of MVPA, and quartile 1 of ST and 0-74 min/week MVPA were associated with higher NC compared to quartile 1 of ST and ≥300 min/week of MVPA. This study suggests that achieving the MVPA recommendations will likely protect against obesity, regardless of ST.

Are the different cut-off points for sitting time associated with excess weight in adults? A population based study in Latin America.

BACKGROUND: Excess weight is increasing worldwide, and in Latin America more than half of the population is excess weight. One of the reasons for this increase has been excessive sitting time. Still, it remains to be seen whether there is an excessive amount of that time in Latin American adults. This study aimed to associate different sitting time cut-off points with the excess weight. METHODS: Data from the Latin American Study of Nutrition and Health (ELANS), a cross-sectional population-based survey conducted in eight Latin American countries, were used. The excess weight indicators used were body mass index, and waist and neck circumferences. Sitting time was obtained using questionnaires and categorized at different cut-off points. Differences between sitting time categories (< 4 or ≥ 4; < 6 or ≥ 6; and < 8 or ≥ 8 hours/day) and excess weight were obtained by Student's t test for independent samples and the association between sitting time categories and different indicators of excess weight were obtained by logistic regression. RESULTS: The median of the sitting time was 420 min/day (IQR: 240-600). There were no significant differences between body mass index (kg/m2) and waist circumference (cm) with categories of sitting time. The mean values of neck circumference (cm) were significantly higher in ≥4, ≥6 and ≥ 8 hours/day than < 4, < 6, and < 8 hours/day of sitting time in the pooled sample. Some distinct differences by country were observed. There were significant differences among excess weight by body mass index (63.2% versus 60.8) with < 8 vs ≥8 hours/day of sitting time. The proportion of excess weight by neck circumference was higher in participants who reported ≥4, ≥6, and ≥ 8 hours/day compared to < 4, < 6, and < 8 hours/day of sitting time. Considering ≥8 hours/day of sitting time, higher odds of excess weight were found evaluated by body mass index (OR: 1.10; 95% CI: 1.01, 1.20) and neck circumference (OR: 1.13; CI 95%: 1.03, 1.24) overall. CONCLUSIONS: Sitting time above 8 hours/day was associated with higher odds of excess weight, even though there were no differences in waist circumference between sitting time categories. TRIAL REGISTRATION: Clinical Trials NCT02226627. (27/08/2014).

Association between breastfeeding, parents' body mass index and birth weight with obesity indicators in children.

BACKGROUND: Childhood obesity is potentially affected by breastfeeding, parents' body mass index and birth weight. Thus, this study aimed to verify the association between breastfeeding, parents' body mass index and birth weight with obesity indicators in children. METHODS: This is a cross-sectional study, including data from 402 schoolchildren between 9 and 11 of age in the city of São Caetano do Sul, Brazil. Parents or guardians answered a questionnaire about breastfeeding (month), birth weight (kg), and parental body weight and height (parents' body mass index [kg/m2] was calculated). Body mass index (kg/m2), waist circumference (cm) and body fat (%), determined via bio-impedance, were measured and used as obesity indicators. Multi-level linear regression models were used to assess the respective associations adjusted for the potential confounders. RESULTS: Considering body mass index of children, the overall prevalence of eutrophic, overweight and obese were 58.2%, 20.9% and 17.2%, respectively. Significant and positive correlations were observed between breastfeeding, maternal as well as paternal body mass index and the children's body mass index, body fat and waist circumference. Birth weight was weakly and positively associated with body mass index and body fat but was not associated with waist circumference. After adjusting for school, sex, age, race/ethnicity, annual household income, sedentary time and moderate-to-vigorous physical activity, maternal body mass index and birth weight were positively associated with children's body mass index (ß: 0.228; 95%CI: 0.142; 0.314 and ß: 0.001; 95%CI: 0.001; 0.002), body fat (ß: 0.484; 95%CI: 0.297; 0.671 and ß: 0.002; 95%CI: 0.001; 0.003) and waist circumference (ß: 0.509; 95%CI: 0.304; 0.715 and ß: 0.003; 95%CI: 0.001; 0.005). Breastfeeding was not associated with any obesity indicators. CONCLUSION: Maternal body mass index and birth weight were associated with children's obesity indicators. The perinatal environment, therefore, appears to be a critical contributor to childhood obesity and public policies need to address parental obesity in order to tackle childhood obesity. TRIAL REGISTRATION: The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) is registered at (Identifier NCT01722500).