Research Data Analyst Associate Center for Food Allergy and Asthma Research Chicago, Illinois, United States
Background: Early introduction of peanut containing food in an infant’s diet is now recommended to prevent peanut allergy. Although the Learning Early about Peanut Allergy trial found no difference in the BMI of children who ate peanut early and those who avoided peanut, there is limited data on the potential impact of early introduction on children’s BMI and risk of obesity outside of clinical trials. Objective: To compare the BMI and obesity/overweight status of children at age 2 between those first fed peanut containing foods at ages 4-7 months and those first fed at age 8 months or later. Design/Methods: The Intervention to Reduce Early Peanut Allergy in Children (iREACH) is a randomized controlled trial measuring the effectiveness of an intervention in increasing pediatric clinicians’ adherence to the 2017 Prevention of Peanut Allergy Guidelines. Randomization occurred at the practice-level. Clinicians in intervention practices received education and clinical support decision tools for implementing guidelines. Caregivers of patients completed a survey about the timing of peanut introduction when their child(ren) reached about 1 year of age. Chi-squared and two-sample t-tests were used to compare the distributions of the first BMI and obesity/overweight measurement at age 2. To overcome the potential endogeneity in the age of peanut introduction, we leverage random variation stemming from the assignment of clinics to the intervention as an instrumental variable for early (ages 4-7 months) versus late (age 8 or later) introduction. Results: BMI data was collected for 1,514 children (n=829 intervention and 685 control) in one of three participating practice networks. Based on electronic health record data, over half of the sample was non-Hispanic White (NHW, 62%) and 24% had unknown race and ethnicity. Early introducers were more likely to be NHW than late introducers (65.1% vs. 48.5%, p< 0.001).
There was no statistically significant difference in mean BMI or percent obese/overweight at age 2 between early and late introducers. IV estimates suggest that early introduction of peanut reduces the BMI of early introducers by 1.0 (p < 0.075) and, although not statistically significant, the probability of being obese or overweight by 0.05 percentage points (p < 0.579).
Conclusion(s): Preliminary evidence from a large sample of predominating NHW children finds no evidence that early peanut introduction implies a higher BMI or probability of obesity or overweight. Further research is warranted to understand the impact among the more racially diverse universe of children participating in the iREACH trial.
