Association between Diet Quality and Health Outcomes among Children in Rural Areas of Northwest China

Isotemporal Substitution Effects of Daily Time Use on Cardiorespiratory Fitness of Children in the OptiChild Study: A Mediation Analysis with Diet Quality

(1) Background: Although daily time-use is associated with diet quality and cardiorespiratory fitness (CRF) in children, their interdependence remains unexplored. This study first examined the associations between reallocating daily movement time and diet quality and CRF, and second the mediating role of diet quality in the relationship between daily time-use and CRF. (2) Methods: This study included 1131 Chinese children (aged 8 to 10 years; median [interquartile range]: 8.5 [8.3, 8.8]) at baseline (September 2022) and 1268 children at the 9-month follow-up (June 2023) from the OptiChild study. Daily durations of moderate-to-vigorous physical activity (MVPA), sleep, and sedentary behavior (e.g., screen time) were self-reported or proxy-reported by parents. Diet quality was assessed via the Diet Quality Questionnaire (DQQ), which uses a 24 h dietary recall and is categorized according to the Global Dietary Recommendations (GDR) score and Food Group Diversity Score (FGDS). The CRF was measured using VO2max after the 20 m shuttle run test. Longitudinal associations between daily time-use, diet quality, and CRF were calculated using isotemporal substitution models. Mediation analyses were used to determine whether diet quality mediated the associations between daily time-use and CRF. (3) Results: Reallocation of 30 min from screen time to MVPA resulted in significant improvements in the GDR score (β baseline = 0.11, p = 0.024; β follow-up = 0.26, p < 0.001), FGDS (β baseline = 0.11, p = 0.006; β follow-up = 0.19, p < 0.001), and CRF (β baseline = 0.40, p < 0.001; β follow-up = 0.26, p = 0.001). Diet quality partially mediated the associations between MVPA, screen time, and CRF. Substituting 30 min of screen time for MVPA led to diet quality mediating a proportion of the association with CRF (GDR score: 11.4%, FGDS: 6.6%). (4) Conclusions: These findings underscore the importance of optimizing daily time-use of MVPA and screen time and improving diet quality to promote physical fitness in school-aged children.

Association between diet quality and risk of stunting among school-aged children in Schistosoma mansoni endemic area of western Kenya: a cross-sectional study

BACKGROUND

Healthy eating habits are essential for improving nutritional status and strengthening immunity against infectious diseases. This study examined the relationship between diet quality and stunting in school-aged children in an infectious disease-endemic area of western Kenya.

METHODS

This cross-sectional study included 260 school-aged children (age 9-17 years) enrolled in primary schools in Mbita Sub-county, western Kenya. The nutritional status was assessed using anthropometric measurements. Dietary intake was measured using food frequency questionnaires and evaluated using the Food Pyramid (FP) score, which indicates adherence to the Kenyan food-based dietary guideline. Information on the children's age, sex, maternal education, and household wealth index was collected using a household-based questionnaire. Infections with the predominant parasites, such as Schistosoma (S.) mansoni, were detected via microscopy. The trend associations of the FP score with food group intake were examined to characterize the dietary intake of this population. Logistic regression analysis was performed to investigate the relationship between stunting and FP score tertiles, adjusted for sociodemographic and economic indicators and parasitic infection status.

RESULTS

Among the studied schoolchildren, 15.0% exhibited stunting, while 76.2% were infected with S. mansoni. The mean FP score was 25.6 out of 50 points. A higher FP score was characterized by a high intake of roots and tubers, dairy products, pulses, and fruits and a low intake of cereals and animal-source foods. The analysis revealed a trend: a lower risk of stunting was evident in groups with elevated FP scores (p for trend = 0.065). However, these trend associations were observable among subjects with either negative or light S. mansoni infection (p for trend = 0.016).

CONCLUSIONS

A higher quality diet, as evaluated by FP scores, was associated with a low risk of stunting among school-aged children. Notably, this association seemed to weaken in the presence of a high burden of S. mansoni infection. It highlights the importance of enhancing dietary quality through the promotion of diverse nutrient-dense foods alongside effective S. mansoni infection control for improved growth. This study contributes fundamental knowledge for understanding the diet-malnutrition relationship in areas endemic for S. mansoni infection.