# Infant Diet Is Associated With BMI Later in Childhood: A Nation‐Wide Mother‐Child Cohort Study in Iceland (ICE‐MCH)

## TL;DR

This study found that better infant nutrition practices, like breastfeeding and proper complementary feeding, are linked to lower obesity risk in children later.

## Contribution

The study introduces an Infant Diet Score and shows its association with childhood obesity risk using nationwide health records.

## Key findings

- Children with lower Infant Diet Scores had higher odds of obesity at 6 and 9 years.
- The association was strongest in the first and second quintiles of the Infant Diet Score.
- Findings suggest promoting infant nutrition guidelines could reduce childhood obesity risk.

## Abstract

Few studies have explored associations between indexes incorporating both breastfeeding and complementary feeding and future risk of overweight/obesity. The aim of this study was to explore associations between a previously developed Infant Diet Score (IDS; higher score reflecting better alignment with breastfeeding and complementary feeding guidelines in the first year of life), and the risk of overweight and/or obesity in childhood. Nutrition and anthropometric data for all children born in Iceland in January 2009 to June 2015 were gathered from national health records. Logistic regression models were used to test associations between IDS and BMI‐for‐age z‐scores (WHO standards). Among children for which the IDS could be calculated, anthropometric data was available for 6,335 children at 2.5 years (thereof 7% with overweight/obesity), 2,486 at 4 years (4% with overweight/obesity), 8,946 at 6 years (19% with overweight and 8% obesity) and 5,626 at 9 years (23% with overweight and 15% obesity). Compared to children in the highest IDS quintile, those in quintiles 1 and 2 had higher odds of obesity at 6 years (aOR: 1.42; 95% CI: 1.05–1.93 and aOR: 1.58; 95% CI: 1.18–2.14) and 9 years (aOR: 1.37; 95% CI: 1.02–1.85 and aOR: 1.46; 95% CI: 1.10–1.94). The same applied for IDS quintile 3 in partly, but not fully adjusted models. Associations were inconsistent at 2.5 years and not observed at 4 years. In this national cohort, lower alignment with infant nutrition guidelines was associated with higher risk of obesity at school age.

Infant dietary practices during the first year of life, particularly breastfeeding, play a role in shaping the risk of obesity later in childhood.Lower alignment with infant nutrition guidelines during the first year of life was associated with increased odds of obesity at school age, specifically at 6 and 9 years.These findings underscore the importance of promoting alignment with established infant nutrition guidelines as a strategy to reduce the risk of childhood obesity. Continued research focusing on obesity in toddlers is also warranted.National health records represent a valuable resource for investigating the relationship between infant nutrition and childhood growth and anthropometric outcomes.

Infant dietary practices during the first year of life, particularly breastfeeding, play a role in shaping the risk of obesity later in childhood.

Lower alignment with infant nutrition guidelines during the first year of life was associated with increased odds of obesity at school age, specifically at 6 and 9 years.

These findings underscore the importance of promoting alignment with established infant nutrition guidelines as a strategy to reduce the risk of childhood obesity. Continued research focusing on obesity in toddlers is also warranted.

National health records represent a valuable resource for investigating the relationship between infant nutrition and childhood growth and anthropometric outcomes.