Associations of dietary patterns with physical growth and obesity in school-age children in rural areas of Jiangsu

Background Obesity among school-age children is an increasingly serious problem. Dietary pattern, as a comprehensive index to measure the dietary intake, is an important factor affecting childhood obesity.

Objective This study is conducted to analyze dietary patterns and explore the associations of dietary patterns with physical growth and obesity in rural school-age children.

Methods A total of 481 children aged 9-10 years in Sheyang Mini Birth Cohort were enrolled. Dietary information was collected using 24-h dietary recall survey. A factor analysis was conducted to define dietary patterns, and dietary pattern scores were divided into three groups by tertiles (T₁, T₂, T₃; from low to high levels). Anthropometric indicators were measured and a generalized line model was used to examine the associations between dietary patterns and body mass index (BMI)-Z scores (a measure of obesity defined by sex- and age- standardized according to the World Health Organization criteria). Logistic regression models were performed to evaluate the association between dietary patterns and children obesity.

Results The prevalence rate of obesity was 17.26% in selected school-age children. Five dietary patterns were identified by the factor analysis, explaining 58.46% of the diet variation, including vegetables and eggs, oil and meat, cereals and oil, fruit and meat, vegetables and fruit rich in vitamin A patterns, respectively. The intakes of energy and nutrients were significantly different among the T₃ groups of the five dietary patterns (P < 0.05). The results of generalized line model showed that the children of the cereals and oil pattern T₃ group had a lower BMI-Z score compared with the T₁ group (total, T₃: T₁, b=-0.44, 95% CI: -0.74﹣-0.15), and the associations were also found in girls (T₂: T₁, b=-0.41, 95% CI; -0.78﹣-0.04; T₃: T₁, b=-0.39, 95% CI: -0.77﹣-0.01); the fruit and meat pattern was significantly positively associated with BMI-Z score (total, b=0.16, 95% CI: 0.01-0.31). The results of logistic regression model showed that the factor score of vegetables and fruit rich in vitamin A pattern negatively correlated with the risk of obesity (total, OR=0.46, 95% CI: 0.27-0.77, P < 0.05; girls, T₂: T₁, OR=0.25, 95%CI: 0.06-1.00, P < 0.05).

Conclusion The prevalence rate of obesity among selected school-age children is high. Contrast to the fruit and meat pattern, the cereals and oil pattern is detrimental to children's growth. The vegetables and fruit rich in vitamin A pattern is related to a low prevalence rate of obesity.