Jenny Jonsdóttir, Birna Thorisdottir, Kristjana Einarsdottir and Inga Thorsdottir
Introduction
Diet scores are useful holistic measures to study associations between diet and health. Our aim was to construct an Infant Diet Score (IDS) for the nation-wide Icelandic-Mother-and-Child-Health-Study (ICE-MCH, N=30,623) and explore associations with demographic factors and BMI.
Methods and data
The ICE-MCH complete nutrition registrations for infants in Iceland born 2009-2015 were used to construct IDS (N=12,848) by six measures, i.e., duration of (i) exclusive and (ii) any breastfeeding; age of introduction of (iii) first solids and (iv) cow’s milk; (v) variety of diet; (vi) use of vitamin D. The range of IDS was zero to five, a higher score represented better alignment to current dietary guidelines. Multiple linear regression tested associations between IDS and demographic factors. Logistic regression tested associations between IDS and BMI-for-age z score (BMIz) at 12 and 18 months (WHO Growth Standards) adjusted for demographic factors.
Results
The median (25th-75th percentile) IDS was 3.4 (2.7-4.0). Primiparity, living outside the capital area, maternal unemployment, parents not cohabiting, multiple births, maternal age < 20 years and pre-pregnancy overweight/obesity were negatively associated with IDS, but demographic factors explained only 4.1% of the variation in IDS. Compared with children in the highest (5th) IDS quintile, children in quintiles 1st and 2nd had increased odds of BMIz >2 at 12 months (aOR:1.86; 95% CI:1.23-2.88), (aOR:1.79; 95% CI:1.18-2.76) and 18 months (aOR:1.44; 95% CI: 1.03-2.04), (aOR:1.74; 95% CI:1.25-2.45).
Conclusions
The IDS is associated with demographic factors and children’s higher BMIz and is a useful holistic measure of diet in infancy.
