Results
UPFs contributed a mean of 15.12% of total energy intake. Higher UPF intake was associated with lower intakes of dietary fiber, protein, potassium, calcium, magnesium, zinc, phosphorus, retinol equivalents, vitamin B1, vitamin B2, vitamin B6, vitamin B12, and vitamin C, and with higher intakes of total fat, saturated fatty acids, and sodium. No significant differences in height percentile, weight percentile, or anthropometric status were observed across UPF quartiles. Among the 746 children with dental examination data, dental caries experience (defined as the presence of at least one decayed or filled tooth) increased from 12.8% in Q1 to 31.2% in Q4 (p < 0.001). After adjustment for age group, sex, total energy intake, and frequency of home cooking, children in Q4 had a higher prevalence of dental caries than those in Q1 (aPR = 2.270, 95% CI: 1.480–3.480; p < 0.001; p for trend < 0.001). Higher UPF intake was also associated with greater constipation-related symptom scores. Compared with Q1, constipation-related symptom scores were 0.900 points higher in Q4 (β = 0.900, 95% CI: 0.330–1.470; p = 0.002). After additional adjustment for dietary fiber intake, this association was attenuated but remained significant (β = 0.680, 95% CI: 0.110–1.260; p = 0.019). In mutually adjusted food-group analyses, higher fruit intake was associated with lower constipation-related symptom scores (β = −0.219, 95% CI: −0.353 to −0.086; p = 0.001), whereas higher biscuit/snack intake was associated with higher constipation-related symptom scores (β = 1.193, 95% CI: 0.441–1.946; p = 0.002). Higher vegetable intake was associated with a lower prevalence of dental caries (aPR = 0.810, 95% CI: 0.660–0.990; p = 0.038).
