As an EAR is not available for total fiber, comparisons were made with the Adequate Intake (AI), which is a value that is observed to be adequate in healthy populations (Institute of Medicine, 2011). Levels of sodium intake were compared with the Upper Limit (UL). The lower NVP-BKM120 manufacturer range of the DRI reference values was used to determine the prevalence of nutrient inadequacy. There were 5195 and 5491 students who completed the FFQ in 2003 and 2011 respectively. Of these students, we excluded 368 (3.4%) students with reported average energy intakes of less than 500 kcal or greater than
5000 kcal per day from the analyses pertaining to dietary outcomes, following established criteria for outlying observations (Willett, 1998). Eating Well with Canada’s Food Guide ( Health Canada, 2008) also provided guidelines for healthy eating according to recommended number of servings for the four food groups: vegetables and fruit, milk and alternatives (yogurt, cheese), grain products (e.g., bread, pasta, cereal) and meat and alternatives (e.g.,
tofu, beans, eggs). Dietary behaviors and intakes from each of the four food groups were determined from the YAQ. Measured body mass index (BMI) was used Ku-0059436 in vitro to define weight status based on the age- and gender-specific cut-off points of the International Obesity Task Force (Cole et al., 2000). Students without height and weight measurements were excluded from the analyses related to weight status. Parents completed home surveys that included information on parental education attainment levels (secondary or less, college, university or above) and household income levels (< $20,000; $20,001–$40,000; $40,001–$60,000; >$60,001). Place of residency else (urban/rural) was determined using Modulators postal codes collected from parent surveys. All statistical analyses were
weighted for non-response bias and represent provincial estimates of the grade 5 student population in public schools across NS. Response weights were calculated based on average household incomes according to postal code data from the 2001 and 2011 census for participants and non-participants, to account for non-response bias due to lower participation rates in residential areas with lower household incomes (Veugelers and Fitzgerald, 2005b). Unadjusted differences between pre- and post-policy implementation for dietary outcomes and weight status were assessed using the Rao–Scott-Chi-square (Rao and Scott, 1981 and Rao and Scott, 1984) or t-test as appropriate. These changes were considered to act as proxies of policy effect. We applied random effects regression methods to account for the clustering of students within schools that are embedded within school boards. Missing values were considered as separate covariate categories but are not presented. Students from schools that did not take part in both years of the study were excluded from the regression analysis.