Sucking behavior in typical and challenging feedings in association with weight gain from birth to 4 Months in full-term infants.

Sucking behavior has been described as an obesity risk marker. Sucking behavior in response to challenge has not been examined as a prospective predictor of infant weight gain. Healthy, full term infants had sucking behavior assessed at ages 2 weeks and/or 2 months via a sucking pressure measurement device in two feeding conditions: during a standard feeding and during a feeding with a more challenging nipple. Weight and length were measured at 2 weeks, 2 months, and 4 months and weight-for-length z-score (WLZ) calculated. Among 45 full term infants, adjusted for age at measurement and time since last feeding, the challenging versus typical feedings differed with regard to amount consumed (54.1g vs. 65.6g, p < .05), maximum sucking pressure (121.3 mmHg vs. 99.2 mmHg, p < .05), mean burst duration (17.5s vs. 28.4s, p < .05), and feeding duration (18.51 min vs. 13.89 min, p < .01). Grams consumed in the challenging, but not typical, feeding, adjusted for age and time since last feeding, predicted rate of change in WLZ from time of measurement to age 4 months (r = 0.46, p = .013 for challenging, r = -0.07, p = .702 for typical). Nipples that are more challenging to suck from change the sucking behavior and intake among full term infants. Infants who consume more when the nipple is more challenging have greater prospective weight gain. This persistent sucking behavior in the face of challenge may reflect that a greater willingness to work for food, a known obesity risk factor, is detectable in early infancy.