Consistency in infants' behavioural signalling of satiation during bottle-feeding

Abstract

Background: Understanding the dynamics of feeding is essential for preventing accelerated weight gain during infancy, a risk factor for obesity.

Objectives: Because infants satiate on larger volumes of cow milk formula (CMF) than CMF enriched with the free amino acid glutamate (CMF + glu), we used this model system to determine whether infants displayed consistent behaviours despite satiating on lower volumes.

Methods: In this laboratory-based, within-subject experimental study of ≤4-month-old infants (n = 41) and their mothers, infants were videotaped while feeding to satiation CMF on one test day and CMF + glu on the other, in counterbalanced order. Each video-recording was analysed frame-by-frame for frequency and timing of behaviours.

Results: Infants' behaviours were consistent in types and frequency but were displayed sooner when feeding CMF + glu compared with CMF. The less responsive the mother's feeding style, the less consistent the infant displayed behaviours across the two formula meals (P = 0.05). Infants who spat up (a possible sign of overfeeding) consumed more formula (P = 0.01) and had less responsive mothers (P = 0.04) compared with the other infants.

Conclusions: Infants are consistent in their behavioural displays during feeding at this developmental age. Regulation of intake and signalling of satiation during bottle-feeding are associated with formula composition and maternal feeding style.

Keywords: Formula feeding; free glutamate; infant feeding; satiation signalling.