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BackgroundParticipation in higher intensity activity (i.e. vigorous physical activity [VPA]) appears more consistently associated with lower adiposity, unfortunately little is known about the nature and patterns of VPA participation in children.ObjectiveTo examine the volume and patterns of vigorous and sedentary activity during different segments of the week (weekend, school-based and out-of-school). We also investigated differences by sex, socioeconomic status (SES) and weight status.DesignA cross-sectional study including 1568 UK children aged 9-10 years.Outcome measuresSedentary activity (mins), total activity (counts/min) and VPA (mins) were measured by accelerometry. Using a series of 2 level mixed effects linear regression models we tested differences across the segmented week (school time [0900-1500] vs. out-of-school time [0700-0900 & 1500-2100]; and weekday vs. weekend); all models were adjusted for sex, weight status (gender- and age-specific body mass index [BMI] cut points), SES, age and accelerometer registered wear time.ResultsBoys and girls accumulated higher VPA out-of-school compared to during school (boys mean ± SD 16.9 ± 9.6 vs 12.6 ± 5.8; girls, 13.1 ± 7.7 vs 8.2 ± 4.0, both p < 0.001); but there were no differences for weekday v weekend VPA (p > 0.05). Less time was spent sedentary on weekdays compared to weekends (p < 0.001). Although boys were more physically active and girls accumulated more sedentary time, the overall pattern in which their physical activity intensity varied across the various day segments was similar when stratified by weight status and SES; and large volumes of sedentary time were observed each hour across the day.ConclusionsThe promotion of VPA during the weekend may hold the greatest promise for increasing VPA. Interventions aimed at increasing physical activity in 9-10 year old children should aim to target all children independent of sex, SES or weight status.

Background A growing body of evidence suggests that physical activity during pregnancy can reduce risk of pregnancy complications. However, factors influencing activity in pregnant Hispanic women, who have high rates of sedentary activity as compared to non-Hispanic whites, are not well characterized. Purpose To assess patterns and correlates of physical activity among 1355 participants in Proyecto Buena Salud, a prospective cohort of pregnant Hispanic women in Massachusetts from 2006 to 2011. Methods Analyses were conducted in 2012. Pre-, early-, mid-, and late-pregnancy physical activity were assessed using the Pregnancy Physical Activity Questionnaire. Women reported the frequency and duration of household/caregiving, occupational, sports/exercise, and transportation activities, and were classified according to compliance with American College of Obstetricians and Gynecologists guidelines for physical activity. Results Household/caregiving activity was the primary mode of pregnancy activity ranging from 56% to 60% of total activity while sports/exercise contributed the least (<10%). Compared to nulliparous women, women with two or more children were 85% less likely to become inactive at any time during pregnancy (OR=0.15 [95% CI=0.04, 0.56], p-trend <0.01). Women with one or more children increased their total physical activity on average 9.73±2.04 MET hours/week and 12.04±2.39 MET-hours/week, respectively, with the onset of pregnancy (p<0.01). Those with the highest levels of total physical activity prior to pregnancy were 87% less likely to become inactive with the onset of pregnancy than those who were inactive prior to pregnancy (OR=0.13 [95% CI= 0.05, 0.29]). Conclusions Findings can inform culturally appropriate interventions designed to reduce pregnancy complications through the promotion of physical activity during pregnancy.

Efforts to prevent childhood obesity by avoiding excess weight gain during infancy have to address mothers' beliefs that babies cannot be overfed, that crying always signals hunger and that growth is determined by genes rather than nutrition. Mothers and healthcare providers have different motivations and understanding these are important in the development of any intervention.

BackgroundThere is increasing recognition that public health strategies to prevent childhood obesity need to start early in life. Any behavioural interventions need to target maternal attitudes and infant feeding practices, This paper describes the development and preliminary validation of a questionnaire to assess maternal attitudes towards infant growth and milk feeding practices.MethodsWe designed a 57-item (19 questions), self-administered questionnaire to measure the following four domains- 1) type of milk feeding, decision making and sources of advice; 2) frequency and quantity of milk feeds; 3) attitudes to infant feeding and growth; and 4) theory-based beliefs about following infant feeding recommendations. Forty mothers completed the questionnaire on two occasions six days apart (to assess test-retest reliability) and then participated in a semi-structured, open-ended telephone interview covering the same domains (to assess criterion validity). Percentage agreement, Cohen's Kappas (for categorical variables) and Spearman's correlation coefficients (for continuous variables) were used to quantify reliability and validity. Internal consistency between theory-based constructs (self-efficacy, outcome expectancy and intention) was quantified by Chronbach's alpha.ResultsOf the 57 questionnaire items 51 (89%) had percentage agreement above 70% indicating good test-retest reliability, and the remaining 6 items had moderate or substantial levels of agreement (kappa 0.41-0.68). Comparing questionnaire with interview coding (validity), percentage agreement was above 66% for 39/57 items (68%). Of the 16 items with percentage agreement below 66%, only five had kappa values below 0.20 (two items had insufficient interview responses). Internal consistency was 0.51, 0.79 and 0.90 for self-efficacy, outcome expectancy and intention respectively.ConclusionsThis questionnaire could be a useful tool in understanding the determinants of infant feeding and the 'causal mechanism' of interventions that target infant feeding practices to prevent early obesity.