Tailored recommendations for infant milk formula intake results in more accurate feeding

Currently available guidelines on the daily formula milk requirements of infants are based on the needs of infants with their growth pattern following the 50th percentile of the weight-for-age growth curve. Hence, current recommendations may not thoroughly detail the needs of infants across the broad spectrum of body weight percentiles. This study aimed to provide stratified recommendations for daily formula milk intake of fully formula-fed infants, across different weight-for-age categories from 0 to 4 months. At first, theoretical age- and gender-specific weight ranges were constructed for infants across five pre-defined weight-for-length percentile categories of the WHO growth standard. Thereafter, total daily energy requirements for each category were calculated and converted to daily formula milk needs. Subsequently, these stratified age- and weight-formula milk recommendations were compared to actual daily and relative formula milk of infants in these categories, retrieved from pooled individual infant formula milk intake data derived from 13 clinical intervention trials. A fitted regression model was used to evaluate differences in volume intakes across body weight categories as well as between theoretically derived and actual intake values. Median daily formula milk volume intake (ml/day) of infants differed significantly across the increasing weight-for-age categories at each time point, with significant differences between small and large infants. Interestingly, the relative daily formula milk volume intake (ml/kg/day) was higher for smaller infants compared to larger infants. The mean daily and relative formula milk intakes demonstrated the same pattern based on theoretical calculations as well as for the actual formula milk intake values retrieved from 13 pooled clinical intervention trials.

Based on theoretical calculations and actual formula intake data, we conclude that larger infants require a significantly higher daily formula milk intake than smaller infants, and we postulate that infants could benefit from more tailored formula milk intake recommendations.

• Adequate energy intake during the infancy period is crucial to support optimal growth and organ development, with the potential for long-lasting health effects. • Current available guidelines on the daily formula milk requirements of infants are based on the needs of infants with their growth pattern following the 50th percentile of the weight-for-age growth curve.

• Based on using both theoretical calculations and actual formula intake data, larger infants require a significantly higher daily formula milk intake than smaller infants. • Exclusive formula-fed infants could benefit from more tailored formula milk intake recommendations, in early infancy.