Background

Although school-based interventions to promote physical activity in adolescents have been suggested in several recent reviews, questions have been raised regarding the effects of the strategies and the methodology applied and for whom the interventions are effective. The aim of the present study was to investigate effects of a school-based intervention program: the HEalth in Adolescents (HEIA) study, on change in physical activity, and furthermore, to explore whether potential effects varied by gender, weight status, initial physical activity level and parental education level.

Methods

This was a cluster randomized controlled 20 month intervention study which included 700 11-year-olds. Main outcome-variable was mean count per minute (cpm) derived from ActiGraph accelerometers (Model 7164/GT1M). Weight and height were measured objectively. Adolescents reported their pubertal status in a questionnaire and parents reported their education level on the consent form. Linear mixed models were used to test intervention effects and to account for the clustering effect of sampling by school.

Results

The present study showed an intervention effect on overall physical activity at the level of p = 0.05 with a net effect of 50 cpm increase from baseline to post intervention in favour of the intervention group (95% CI −0.4, 100). Subgroup analyses showed that the effect appeared to be more profound among girls (Est 65 cpm, CI 5, 124, p = 0.03) and among participants in the low-activity group (Est 92 cpm, CI 41, 142, p < 0.001), as compared to boys and participants in the high-activity group, respectively. Furthermore, the intervention affected physical activity among the normal weight group more positively than among the overweight, and participants with parents having 13–16 years of education more positively than participants with parents having either a lower or higher number of years of education. The intervention seemed to succeed in reducing time spent sedentary among girls but not among boys.

Conclusions

A comprehensive but feasible, multi-component school-based intervention can affect physical activity patterns in adolescents by increasing overall physical activity. This intervention effect seemed to be more profound in girls than boys, low-active adolescents compared to high-active adolescents, participants with normal weight compared to the overweight, and for participants with parents of middle education level as opposed to those with high and low education levels, respectively. An implementation of the HEIA intervention components in the school system may have a beneficial effect on public health by increasing overall physical activity among adolescents and possibly among girls and low-active adolescents in particular.

Background

Studies on the health benefits from breastfeeding often rely on maternal recall of breastfeeding. Although short-term maternal recall has been found to be quite accurate, less is known about long-term accuracy. The objective of this study was to assess the accuracy of long-term maternal recall of breastfeeding duration.

Methods

In a prospective study of pregnancy and birth outcome, detailed information on breastfeeding during the child’s first year of life was collected from a cohort of Norwegian women who gave birth in 1986–88. Among 374 of the participants, data on breastfeeding initiation and duration were compared to recalled data obtained from mailed questionnaires some 20 years later. Intraclass correlation coefficient (ICC), Bland-Altman plot, and Kappa statistics were used to assess the agreement between the two sources of data. Logistic regression was used to assess predictors of misreporting breastfeeding duration by more than one month.

Results

Recorded and recalled breastfeeding duration were strongly correlated (ICC=0.82, p < 0.001). Nearly two thirds of women recalled their breastfeeding to within one month. Recall data showed a modest median overestimation of about 2 weeks. There were no apparent systematic discrepancies between the two sources of information, but recall error was predicted by the age when infants were introduced to another kind of milk. Across categories of breastfeeding, the overall weighted Kappa statistic showed an almost perfect agreement (κ = 0.85, 95% confidence interval [CI] 0.82 – 0.88).

Conclusion

Breastfeeding duration was recalled quite accurately 20 years after mothers gave birth in a population where breastfeeding is common and its duration long.

Objective

The aim of this study was to evaluate a short food frequency questionnaire (FFQ) against a four-day precoded food diary (PFD) with regard to frequency of food intake among Norwegian 9- and 13-year-olds.

Subjects and design

A total of 733 9-year-olds and 904 13-year-olds completed first a short FFQ and one to two weeks later a four-day PFD. The short FFQ included questions about 23 food items, including different drinks, fruits, vegetables, bread, fish, pizza, sweets, chocolate and savoury snacks. The PFD covered the whole diet.

Results

When comparing mean intake from the PFD with comparable food items in the FFQ, all food items showed that increasing intake measured with the PFD corresponded with increasing intake with the short FFQ. However, participants reported a significantly higher frequency of intake for most foods with the short FFQ compared with PFD, except for soft drinks with sugar and sweets. The median Spearman correlation coefficient between the two methods was 0.36 among the 9-year-olds and 0.32 among the 13-year-olds. Often eaten foods such as fruits and vegetables had higher correlations than seldom eaten foods such as pizza and potato chips. The median correlation coefficients for drinks alone were higher (r=0.47) for both age groups.

Conclusions

Results indicate that the short FFQ was able to identify high and low consumers of food intake and had a moderate capability to rank individuals according to food intake. Drinks, fruits and vegetables had better correlations with the PFD than infrequently eaten food items.

Background

Weight loss and increased physical fitness are established approaches to reduce cardiovascular risk factors. We studied the reduction in BMI z-score associated with improvement in cardiometabolic risk factors in overweight and obese children and adolescents treated with a combined hospital/public health nurse model. We also examined how aerobic fitness influenced the results.

Methods

From 2004-2007, 307 overweight and obese children and adolescents aged 7-17 years were referred to an outpatient hospital pediatrics clinic and evaluated by a multidisciplinary team. Together with family members, they were counseled regarding diet and physical activity at biannual clinic visits. Visits with the public health nurse at local schools or at maternal and child health centres were scheduled between the hospital consultations. Fasting blood samples were taken at baseline and after one year, and aerobic fitness (VO2peak) was measured. In the analyses, 230 subjects completing one year of follow-up by December 2008 were divided into four groups according to changes in BMI z-score: Group 1: decrease in BMI z-score≥0.23, Group 2: decrease in BMI z-score≥0.1-< 0.23, Group 3: decrease in/stable BMI z-score≥0.0-< 0.1, Group 4: increase in BMI z-score (>0.00-0.55).

Results

230 participants were included in the analyses (75%). Mean (SD) BMI z-score was reduced from 2.18 (0.30) to 2.05 (0.39) (p < 0.001) in the group as a whole. After adjustment for BMI z-score, waist circumference and gender, the three groups with reduced BMI z-score had a significantly greater reduction in HOMA-IR, insulin, total cholesterol, LDL cholesterol and total/HDL cholesterol ratio than the group with increased BMI z-score. Adding change in aerobic fitness to the model had little influence on the results. Even a very small reduction in BMI z-score (group 3) was associated with significantly lower insulin, total cholesterol, LDL and total/HDL cholesterol ratio. The group with the largest reduction in BMI z-score had improvements in HOMA-IR and aerobic fitness as well. An increase in BMI z-score was associated with worsening of C-peptide and total/HDL cholesterol ratio.

Conclusions

Even a modest reduction in BMI z-score after one year of combined hospital/and public health nurse intervention was associated with improvement in several cardiovascular risk factors.