Diet quality of Norwegian children at 3 and 7 years: changes, predictors and longitudinal association with weight

Background/Objectives Poor diet quality in early life can have long-term health effects, but the evidence is largely from cross-sectional studies. Our objective was to examine diet quality of Norwegian children by applying a-priori diet quality indices, identify early life determinants and examine prospective associations with overweight. Subjects/Methods We included 34,074 preschoolers (3-year-olds) and 18,350 school-aged children (7-years-olds) from the prospective, population-based Norwegian Mother, Father and Child Cohort Study. Diet quality was assessed as (i) adherence to a Mediterranean diet, estimated by the food frequency-based Mediterranean Diet Score (fMDS, score range: 0-6) and (ii) by the diet quality index (DQI, score range: -33% to 100%), reflecting compliance to food-based dietary guidelines. In multivariate analyses we explored perinatal and childhood characteristics as potential determinants of diet quality. We used logistic regression to examine the associations between diet quality at 3 years and BMI status at 8 years, adjusting for relevant confounders and diet quality at 7 years. Results One in three children had high MD adherence at 3 and 8 years, and DQI (mean 60%) at 3 and 7 years was strongly correlated (r = 0.48, p < 0.001). Short breastfeeding duration, physical activity and sleep duration and long screentime at 18 months were associated with 2-3% lower DQI at 3 years. At both ages, maternal diet quality was the strongest prospective predictor of DQI (beta = 5%, 95% CI = 4.7, 5.2 and beta = 3.1%, 95% CI = 2.8, 3.4), and screentime was the strongest cross-sectional predictor (beta = -5.2%, 95% CI = -5.9, -4.5 and beta = -4.1%, 95% CI = -5.0, -3.2). High DQI score at 3 years, but not MD adherence, was associated with a lower risk for overweight (including obesity) at 8 years, compared to low DQI (lower tertile) (adjusted OR = 0.77, 95% CI = 0.62, 0.96). Conclusions Our study provides evidences that high diet quality in early childhood may reduce the risk for overweight in later childhood, independent of the current dietary behaviors.

Automated summary

This study from the Norwegian cohort found that high diet quality in early childhood may reduce the risk for overweight in later childhood. Maternal diet quality was the strongest predictor of children's diet quality, while excessive screen time was a significant predictor of lower diet quality.