Isabel Mourão

Prevalence and risk factors for overweight and obesity in Portuguese children.

Aim: To identify risk factors for overweight and obesity in Portuguese children.

Dietary calcium and body mass index in Portuguese children

Objective:The objective of our study was to assess nutritional intake in school children (7–9-y-old) and relate calcium intake to body mass index (BMI).Design:This study was a cross-sectional analysis.Setting:The data were derived from a community-based survey of children from primary schools of Portugal.Subjects:In all, 3044 Portuguese children (1503 girls and 1541 boys) from a community-based sample of 7–9-y-olds.Methods:Height and weight were measured according to international standards, and BMI was calculated. Childrens parents completed a self-administered questionnaire that provided information on general family background characteristics and childrens physical activity. Childrens dietary intake was measured using a 24-h dietary recall. Calcium intake was expressed as the calcium-to-protein ratio, and regression analysis was used to estimate the association between calcium intake and BMI, adjusting for energy intake and confounders.Results:The prevalence of children with calcium intake below the Dietary Reference Intake was higher in girls (36.4 vs 33.0%, P=0.053). Calcium-to-protein ratio predicts BMI only in girls (β=−0.052, P=0.002), even after adjusting for age, energy intake, parental education, and physical activity.Conclusion:We found an inverse relationship between calcium intake and BMI only in girls. These data reinforce the need for controlled trials to assess the effects of dietary calcium on body mass in each gender.Sponsorship:Fundação Ciência e Tecnologia POCTI/ESP/43238/2001.

Type-specific screen time associations with cardiovascular risk markers in children

BACKGROUND There is evidence that TV time may have stronger associations with cardiovascular risk markers than other types of screen time, but most studies focus on TV, or total screen time. PURPOSE To examine associations between types of screen time and cardiovascular risk markers in school-age children. METHODS Cross-sectional study of 2515 school children in Portugal (aged 2-12 years, data collected in 2009 and 2010). Three types of screen time (TV, electronic games, and PC time) were collected through a questionnaire, and data on three cardiovascular risk markers (resting heart rate; diastolic blood pressure [DBP]; and systolic blood pressure [SBP]) were collected by a trained fieldworker. Complex-samples generalized linear models were run for each combination of screen time predictor and cardiovascular risk outcome, and a clustered cardiovascular risk score, adjusting for potential confounders (including physical activity). Analyses were conducted in 2011 and 2012. RESULTS TV viewing, but not PC or electronic games time, was associated positively with clustered cardiovascular risk score, DBP, and SBP after adjustment for all covariates. Watching TV for >2 hours/day (compared to <1 hour/day) was associated with higher DBP (coefficient, logged and back-transformed 0.02, 95% CI=0.00, 0.04, linear trend p=0.003); SBP (logged and back-transformed 0.02, 95% CI= -0.01, 0.05, p=0.009), and clustered cardiovascular risk score (0.13, 95% CI=0.02, 0.24, p<0.001). CONCLUSIONS TV viewing, but no other type of screen time, was associated positively with cardiovascular risk markers independently of physical activity. Studies using a single marker of screen time or sedentary behavior may conceal screen time type-specific associations.

Associations between indicators of screen time and adiposity indices in Portuguese children.

OBJECTIVES To examine associations between three types of screen time (TV, electronic games (EG), and personal computer (PC)) and two proxies of adiposity (body mass index (BMI) and sum of skinfolds) in children. DESIGN The sample comprised 17,509 children aged 2-13 years who participated in the 2009/10 Portuguese Prevalence Study of Obesity in Childhood. METHODS Complex samples generalised linear models, using school as a cluster variable were ran separately for each combination of ST predictor and adiposity-related outcome, adjusting for covariates including age, sex, physical activity, diet, and parental factors. Missing values in predictors and covariates were imputed. RESULTS Watching TV for >2h/day compared to <1h/day was associated with higher age- and sex-specific BMI standard deviation score (coefficient: 0.06, 95% CI: 0.01 to 0.12, linear trend p=0.008) and sum of skinfolds (logged and back transformed 0.04, 0.02 to 0.07, p=<0.001). We also found weak evidence for an inverse association between PC and BMI. CONCLUSIONS Associations between ST and adiposity differ by both type of ST and type of adiposity marker. Only TV viewing was consistently associated with adiposity. Studies using a single adiposity marker looking at total screen time or total sedentary behaviour time may miss or confound type-specific associations.

The associations of SES, obesity, sport activity, and perceived neighborhood environments: Is there a model of environmental injustice penalizing portuguese children?

This study analyses the associations between childrens obesity, sports activity (SA), and perceived environmental characteristics with the childrens SES.

Active commuting and its associations with blood pressure and adiposity markers in children.

OBJECTIVE The positive impacts of active travel on health markers still require further research, especially in youth populations with higher risk of obesity. The present study aimed to analyze the associations between blood pressure and adiposity risk (BPAR) and active travel to school in children. METHODS The sample comprised 665 Portuguese children (345 boys) aged 7-9 years. Data on height, weight, and skinfold thickness were collected by a trained fieldworker as well as data on BPAR between March 2009 and January 2010 (data were analyzed in 2012-2013). Information on mode and duration of travel to school (i.e. exposure) was gathered by questionnaire. Outcome variables were statistically normalized and expressed as Z scores. A BPAR score was computed as the mean of the Z scores. Multiple linear regression, with adjustments for confounders, was used. RESULTS Active commuting was inversely associated with BPAR after adjustment for several potential confounders. After adjusting for BMI, the strength of the relationship between BPAR and active commuting was significantly improved (p≤0.01). CONCLUSIONS Findings showed an independent association between the clustered BPAR and active commuting in children aged 7-9 years.

Parental perceptions of neighborhood environments, BMI, and active behaviors in girls aged 7-9 years.

Habitual physical activity (PA) may be influenced by a broad range of neighborhood, school, community, and family factors. Young people, particularly girls, tend to show lower habitual PA than boys and should be a target for prevention strategies aimed at healthy lifestyles. The purpose of this study was twofold: (1) to determine which perceived attributes about neighborhoods are related to active behaviors; (2) to analyze which perceived attributes about neighborhoods are related to body mass index (BMI) of children.

Waist-to-height ratio and its association with TV viewing in a sample of Portuguese children aged 7–9 years

During the past decades, increased TV viewing and reduced physical activity (PA) levels may have contributed to the increased prevalence of pediatric obesity. This study aimed to analyze the association between TV viewing and central adiposity risk in Portuguese children.

Eating away from home: a risk factor for overweight in children

The present study examined the association between childhood overweight, children’s meals and eating out in three types of restaurants (traditional Portuguese food restaurant, fast-food restaurant and snack bar). A representative sample of Portuguese children (5706 boys; 5950 girls aged 6–11 years) was used for this analysis and an ethnographic study with 233 interviews of the owners of snack bars in Coimbra (Portugal). Weight and height were measured (body mass index was consequently calculated). A familial and nutritional questionnaire was filled out by parents. Logistic regressions were used. Findings revealed that eating out at snack bars may be a risk for children’s health because those who eat out at these food establishments have a 21% higher risk of being overweight than those peers who do not eat out at snack bars. In conclusion, findings revealed a statistically significant association between overweight and eating out at snack bars in boys.

The association of irregular sleep habits with the risk of being overweight/obese in a sample of Portuguese children aged 6-9 years

The consequences of irregular sleep duration at younger ages remains uncertain, especially when we consider shorter and longer than recommended sleep durations. Therefore, the present study aimed to analyze the association between healthy sleep duration and risk of obesity in Portuguese children.