Effect of the Shaping Healthy Choices Program, a Multicomponent, School-Based Nutrition Intervention, on Physical Activity Intensity.

OBJECTIVE: Physical activity has been shown to have a wide range of beneficial health effects, yet few youth meet the United States physical activity recommendation of 60 minutes of moderate-to-vigorous physical activity (MVPA) everyday. The objective of this study was to determine whether physical activity patterns improved in a subsample of fourth-graders participating in the multicomponent intervention, the Shaping Healthy Choices Program (SHCP). METHODS: At pre- and post-intervention assessments, youth at the control and intervention schools wore a Polar Active monitor on their nondominant wrist 24 h/d for at least 2 consecutive days. Multiple linear regression was used to evaluate change in physical activity by adjusting for covariates and other potential confounders, including ethnicity/race, household income, and sex. Statistical significance was set at p < 0.05. RESULTS: Mean minutes of MVPA significantly increased at the intervention school (22.3 + 37.8; p = 0.01) and at the control school (29.1 + 49.5; p = 0.01). There were no significant differences in the change in MVPA between the schools. Youth at the intervention school significantly decreased mean minutes in sedentary activity compared to the controls (p = 0.02). CONCLUSIONS: Youth who participated in the SHCP decreased time spent in sedentary activity and increased very vigorous physical activity from pre- to post-intervention, while these changes were not observed at the control school. The overall small physical activity intensity pattern shift supports that physical activity is an important area to target within a multicomponent nutrition intervention aimed at preventing childhood obesity.

Associations Among Fatty Acids, Desaturase and Elongase, and Insulin Resistance in Children.

OBJECTIVES: Fatty acid profiles and desaturase (SCD-16, SCD018, D5D, D6D) and elongase (ELOVL6) enzyme activity have been associated with adiposity and metabolic disease. While this has been studied in adults, few studies have included children. The objective of this study was to evaluate these markers in children and identify relationships with markers of metabolic health. It was hypothesized that these lipid markers would be correlated to adiposity and metabolic disease. METHODS: This study was a cross-sectional analysis of fourth- and fifth-grade children (n = 86, aged 9-12) participating in a comprehensive nutrition program. Any student enrolled in the program was eligible for inclusion in this study. Fasting plasma was collected and analyzed for total fatty acids, glucose, insulin, and full lipid panels. Insulin resistance was estimated using calculated homeostatic model assessment for insulin resistance (HOMA-IR) values. RESULTS: There were no differences in lipid markers, glucose, insulin, or HOMA-IR among children classified as normal weight, overweight, or obese. SCD-16, D5D, and ELOVL6 activity was significantly correlated to HOMA-IR values (r = 0.39, p = 0.001; r = -0.33, p = 0.006; r = -0.37, p = 0.005, respectively). In regression analysis, body mass index for age percentile, D6D activity, ELOVL6 activity, and systolic blood pressure were the most significant predictors of HOMA-IR values (adjusted r2 = 0.39, p ≤ 0.001). CONCLUSIONS: There was no relationship between these lipid markers and adiposity in this population; however, there were correlations with HOMA-IR. Regardless of adiposity, there may be underlying changes in fatty acid and lipid metabolism associated with the development of metabolic diseases.