The introduction of solid food and growth in the first 2 y of life in formula-fed children: analysis of data from a European cohort study

Background: Early introduction of solid food has been suspected to induce excessive infant energy intake and weight gain. Objective: The objective of this study was to test whether introduction of solid foods influences energy intake or growth. Design: Healthy, formula-fed infants who were recruited in 5 European countries were eligible for study participation. Anthropometric measurements were taken at recruitment and at 3, 6, 12, and 24 mo. Time of introduction of solid foods and energy intake were determined by questionnaires and 3-d weighed food records at monthly intervals. Age at introduction of solid food was categorized into 4 groups: <= 13 wk, 14-17 wk, 18-21 wk, and >= 22 wk. Results: Of 1090 recruited infants, 830 (76%) had data available for age at first introduction of solid food, and 671 (61%) completed the study until 24 mo of age. The median age at introduction of solid food was 19 wk. The time of introduction of solid foods was associated with country, sex, birth weight, parental education and marital status, and maternal smoking. Energy intake was higher in the first 8 mo of life in children with solid-food intake. Solid-food introduction did not predict anthropometric measures at 24 mo. Growth trajectories differed significantly: children with solid-food introduction in the first 12 wk experienced early catch-up growth, whereas those introduced to solid food at >22 wk of age grew more slowly and stayed on lower trajectories. Conclusions: Solid foods do not simply replace infant formula but increase energy intake. Time of introduction of solid food has little influence on infant growth. This trial was registered at clinicaltrials.gov as NCT00338689. Am J Clin Nutr 2011;94(suppl):1785S-93S.