Objective assessment of childhood adherence to Canadian physical activity guidelines in relation to body composition
Bibliographic record
Abstract
Low levels of childhood physical activity (PA) are a contributing factor to obesity. The objective of this study was to determine the adherence of children to PA guidelines in relation to body composition. Body fat (Slaughter equation) and body mass index (BMI) were determined during the school year (n = 251, ages 8-11 y). Daily energy expenditure (EE, kcal.kg-1.d-1) and activity time (AT, min.d-1) above moderate and vigorous intensity thresholds were assessed (accelerometry). Using EE criteria, 35.9% expended < 3.0 kcal.kg-1.d-1, 27.9% expended between 3.0 and 5.9 kcal.kg-1.d-1, 13.5% expended between 6.0 and 7.9 kcal.kg-1.d-1, and 22.9% expended >or= 8.0 kcal.kg-1.d-1. Using AT criteria, 52.2% accumulated < 30.0 min, 31.1% accumulated 30.0-59.9 min, 12.7% accumulated 60.0-89.9 min, and 4.0% accumulated >or=90.0 min of AT. The EE corresponding to accumulation of AT > 90 min was 14.8 kcal.kg-1.d-1. The AT corresponding to >or= 8 kcal.kg-1.d-1 was 73.0 min. Inverse relationships were observed between EE and body fat (p = 0.0004), BMI (p = 0.002), mass (p = 0.008), and fat mass index (FMI) (p = 0.001), as well as between AT and body fat (p = 0.001), BMI (p = 0.008), mass (p = 0.017), and FMI (p = 0.002). Controlling for BMI, FMI was inversely related to EE (p = 0.049) and AT (p = 0.039). Fat-free mass index and AT were positively related (p = 0.038). Physical activity had beneficial effects on body composition for children independent of BMI. The relationship between AT and daily EE guidelines was rationalized (60 min.d-1 with 8 kcal.kg-1.d-1) and demonstrated association with acceptable body composition. The 60 min.d-1 of moderate activity may be a more suitable initial target than 90 min.d-1, as so few children met the upper tiers of PA guidelines.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".