Timing of Introduction to Solid Food, Growth, and Nutrition Risk in Later Childhood.

OBJECTIVE: To evaluate the relationship between the timing of infant cereal introduction between 4 and 6 months of age and growth and dietary intake in later childhood. STUDY DESIGN: A longitudinal cohort study was conducted among healthy children 0-10 years of age participating in The Applied Research Group for Kids cohort study between June 2008 and August 2019 in Toronto, Canada. RESULTS: Of 8943 children included, the mean (SD) age of infant cereal introduction was 5.7 (2.1) months. In the primary analysis, children who were introduced to infant cereal at 4 vs 6 months had 0.17 greater body mass index z score (95% CI 0.06-0.28; P = .002) and greater odds of obesity (OR 1.82; 95% CI 1.18-2.80; P = .006) at 10 years of age. In the secondary analysis, children who were introduced to infant cereal at 4 vs 6 months had 0.09 greater height-for-age z score (95% CI 0.04-0.15; P = .002) at 1 year of age, an association that was not observed at 5 or 10 years of age. Children who were introduced to infant cereal at 4 vs 6 months had greater nutrition risk which was primarily determined by a less-favorable eating behavior score at 18 months to 5 years of age (0.18 units higher; 95% CI 0.07-0.29; P = .001). CONCLUSIONS: Introduction of infant cereal at 4 vs 6 months was associated with greater body mass index z score, greater odds of obesity, similar height-for-age z score, and less favorable eating behavior. These findings support recommendations for introducing solid food around 6 months of age.