Effects of egg as an early complementary food on growth of 6-to 9-month-old infants: a randomised controlled trial

Objective:To assess the effect of daily egg consumption for six months on linear growth (primary outcome), weight-for-age, weight-for-length, mid-upper arm circumference-for-age, head circumference-for-age Z-scores, gross motor milestones development, anaemia and iron status (secondary outcomes) in a low socioeconomic community.Participants:Infants aged 6 to 9 months living in the peri-urban Jouberton area, in the Matlosana Municipality, South Africa.Design:A randomised controlled trial with a parallel design was implemented. Eligible infants were randomly allocated to the intervention (n 250) receiving one egg/day and the control group (n 250) receiving no intervention. The participants were visited weekly to monitor morbidity and gross motor development, with information on adherence collected for the intervention group. Trained assessors took anthropometric measurements, and a blood sample was collected to assess anaemia and iron status. There was blinding of the anthropometric assessors to the groups during measurements and the statistician during the analysis.Results:Baseline prevalence of stunting, underweight, wasting, overweight and anaemia was 23 center dot 8 %, 9 center dot 8 %, 1 center dot 2 %, 13 center dot 8 % and 29 center dot 2 %, respectively, and did not differ between groups. Overall, 230 and 216 participants in the intervention and control groups completed the study, respectively. There was no intervention effect on length-for-age, weight-for-age, weight-for-length Z-scores, gross motor milestone development, anaemia and iron status.Conclusions:Daily egg intake did not affect linear growth, underweight, wasting, motor milestones development, anaemia and iron status. Other interventions are necessary to understand the effect of animal-source food intake on children's growth and development. This trial was registered at https://clinicaltrials.gov/ (NCT05168085).