Hypothesis/purpose of study:The purpose of this study was to identify key dietary and physical activity behavior patterns in a group of 9-11 year old children and compare them to established goals/recommendations for this population. In addition, the authors examined the influence of peers on health behaviors in this group.
Subjects:A total of 106 children (64 girls, 42 boys) 9-10 years of age at the start of the study were recruited from 3 middle income schools in southwest London, UK.
Experimental design:Longitudinal, observational study (non-experimental)
Protocol:The study began in the summer of 2007 and the children were measured in 2007 and 2008 at the same time of year. Measurements included: height and weight, dietary intake (3-day food records), physical activity (3-day recording period with a pedometer), and a questionnaire regarding peer influences on behavior (4 questions taken from the validated Children’s Physical Activity Correlates instrument). Reported dietary intake variables (energy, sodium, iron, calcium) were adjusted upward by a factor of 1.25 to account for underreporting.
- Body mass index values increased as expected for both boys and girls from 2007 to 2008, but the means were within the normal range (BMIs of 17-19 kg/m2, z-scores 0.24 to 0.5).
- Adjusted energy intakes for the boys were 2,151 kcal/day in 2007 and 1,796 kcal/day in 2008, neither of which was high enough to meet UK recommendations. For the girls, the adjusted energy intakes were 1,968 kcal/day in 2007 and 1835 kcal/day in 2008; only the adjusted energy intake in 2007 met the UK recommendations.
- Adjusted sodium intakes (~2,600 mg/day for both boys and girls) exceeded the Recommended Nutrient Intake (RNI) values for that population in both years.
- Adjusted iron intakes were generally between 8.75 and 10 mg/day for both boys and girls, but the iron intakes in boys in 2007 (11.3 mg/day) did meet the RNI.
- Likewise, the adjusted calcium intakes were typically below the RNI for boys (768-926 mg/day) and girls (778-866 mg/day), although the 866 mg/day intake value was high enough to meet the RNI.
- Saturated fat intake ranged from 13-15% of energy, somewhat above a typical goal of no more than 10% of energy.
- Fruit and vegetable intake also did not meet recommendations.
Step counts for physical activity averaged about 12,000 per day for boys and 10,000 per day for girls, which was below the goals of 15,000 per day for boys and 12,000 per day for girls. Peers were found to influence physical activity levels but not dietary intake.
This study suggested that, in this cohort, 9-11 year-old children were generally taking in insufficient dietary energy, calcium, and iron and were exceeding recommendations for sodium and saturated fat intake. Physical activity was also somewhat lower than recommended levels, but the article did not mention if children in the study were involved in athletic programs of any kind. The lack of peer influence on dietary intake contrasted with some previous studies, but agreed with others. Results from this study are difficult to generalize due to small sample size and lack of diversity regarding socioeconomic status and possibly other factors such as race.