Neurobehavior and neuroendocrine regulation of hunger and satiety in the newborn

The recognition of hunger signals in the newborn is a fundamental element in neonatal care and neurobehavioral development during the postnatal period. The ability of caregivers to correctly interpret the behavioral, physiological, and vocal manifestations that precede the request for nourishment ensures optimal feeding, supports the self-regulation of caloric intake and promotes the establishment of a secure attachment. Crying, although immediately evident, emerges late compared to early signals such as rooting, lip sucking, oro-manual movements and bringing hands to the mouth, which constitute reliable indicators of hunger.

Neuroendocrine circuits of hunger and satiety

The neuroendocrine circuits involved in the regulation of hunger and satiety are highly integrated. The hypothalamus, through the arcuate nucleus, the ventromedial area and the paraventricular nucleus, integrates peripheral and central signals of energy status. Gastric ghrelin gastric activates orexigenic AgRP/NPY neurons promoting sucking and active searching for milk, while leptin and insulin modulate the activity of POMC/CART neurons, contributing to the sensation of satiety. Cholecystokinin and peptide YY provide feedback of gastric distension and modulate the duration of feedings. These signals interact with dopaminergic and serotonergic circuits that regulate motivation, reward, and food-seeking behavior, ensuring an adaptive homeostatic balance as early as the first weeks of life. The hypothalamic-pituitary-adrenal axis also contributes to the modulation of stress and the regulation of autonomic tone, influencing feeding behavior and emotional responses during feeding.

Responsive feeding and development of self-regulation

The development of self-regulation of energy intake depends on a consistent response to hunger signals. Responsive feeding allows the newborn to modulate the frequency and duration of feedings according to metabolic needs, stimulates maternal milk production and promotes the maturation of dopaminergic circuits involved in reward and motivation. In addition to motor signals, facial expressions, variations in muscle tone and mild vocalizations complete the language of the newborn, which requires continuous observation and constant interactions to allow for adequate nutritional regulation.

Caregiver–newborn relationship and socio-emotional development

The interaction between caregiver and newborn has repercussions on socio-emotional and neurobehavioral development. Responding to hunger and satiety signals with consistency promotes secure attachment, regulates stress levels and reinforces the couple relationship. During the first postnatal weeks, it is fundamental that parents consider the child as a priority commitment, carve out relaxation breaks, manage daily tasks gradually and rely on the support of partners, relatives or professionals. Open communication between parents generates an emotionally positive environment, optimizing the interpretation of neonatal signals and the establishment of consistent behavioral patterns.

Scientific evidence and institutional recommendations

The advanced understanding of hunger signals implies the integration of neuroendocrine, behavioral, and physiological data. Monitoring weight growth, sucking quality, feeding duration and rest breaks provides precise indications on the satisfaction of nutritional needs and the development of self-regulation. The adoption of strategies based on on-demand breastfeeding is supported by evidence from the World Health Organization and national guidelines, ensuring an approach that promotes growth, cognitive development, and emotional balance of the newborn.

The Italian Society of Neonatology (SIN) has for years promoted in-depth knowledge of the newborn’s behavioral signals, including those of hunger and satiety, as an integral part of proper neonatal care practice and appropriate breastfeeding support. Although SIN publications do not contain guidelines exclusively dedicated to decoding nutritional signals, these components are included in official documents and clinical protocols on the promotion of breastfeeding and the care of the mother-newborn dyad.

The Position Statement on breastfeeding and the use of maternal/human milk, prepared jointly by SIN and other Italian scientific societies, reaffirms the importance of fostering an early and responsive start to breastfeeding, which requires careful observation of the newborn’s hunger signals and the dynamic adaptation of the breastfeeding practice to their physiological needs. This document provides guidance on how to support the mother and newborn in the breastfeeding initiation phase, emphasizing the role of healthcare staff in recognizing and facilitating the response to hunger and satiety signals to sustain effective and continuous breastfeeding activity.

In the context of breastfeeding promotion campaigns, such as World Breastfeeding Week, SIN has reaffirmed the need to consolidate support networks around mothers, encouraging practices such as rooming-in and skin-to-skin contact as early as the first hours of life, interventions that facilitate the perception and early response to hunger signals of the newborn and favor the establishment of on-demand breastfeeding. In this context, SIN includes the observation of behavioral signals as part of personalized care for the mother-newborn dyad.

The SIN, also through the Corporate Policy Project for Breastfeeding (PAA), has developed and supported guidelines and corporate protocols for the promotion of breastfeeding in Italian Birth Centers. These protocols include recommendations for the education and training of healthcare staff in relation to latching skills, feeding management and the decoding of behavioral signals of the newborn, improving the ability to recognize and respond promptly to hunger and satiety signals. The implementation of these protocols is considered a key component for increasing exclusive breastfeeding rates at discharge and supporting prolonged breastfeeding.

Finally, SIN emphasizes that the promotion of breastfeeding and knowledge of the newborn’s hunger and satiety signals must be supported by specific training of healthcare staff, including midwives, neonatologists, pediatricians and nurses, to ensure an integrated approach to the care of the mother and child from birth and during the postpartum period, as indicated in care standards and in professional updating initiatives promoted at the national level.

The recognition of hunger and satiety signals, the interpretation of the neurobehavioral language of the newborn and the consistent response of caregivers constitute fundamental elements for advanced neonatal care, ensuring optimal feeding regulation, psychophysiological well-being and the integral development of the child. Integrated attention to these aspects allows for supporting the establishment of consistent behavioral patterns, a secure attachment and a harmonious neurobehavioral development in accordance with the best scientific evidence and international guidelines.