Prevention of Overfeeding During Infancy

描述（由申请人提供）： 本申请涉及广泛的挑战领域（01）行为、行为变化和预防以及特定的挑战主题01-DK-102：发现与肥胖相关的行为机制。越来越明显的是，预防儿童肥胖必须从生命的早期开始，因为在过去的20年里，美国儿童超重的流行率甚至在最年轻的年龄组中也有所增加。后来肥胖的关键危险因素之一是婴儿期体重快速增加;相关的行为因素是父母的养育方式和相关的婴儿喂养方法。过度喂养婴儿，特别是那些用奶瓶喂养的婴儿，可能会导致体重迅速增加，但关于如何有效解决这个问题的信息很少。有充分的证据表明，配方奶粉喂养的婴儿比母乳喂养的婴儿消耗更多的能量和增加更多的体重，即使在生命的最初几个月。此外，母乳喂养的婴儿患儿童肥胖症的风险较低，尽管其机制尚不清楚。一个潜在的机制是，从瓶子里喂食可能会鼓励过量摄入。母乳喂养的婴儿能够根据内部饱腹感的线索自我调节摄入量，但奶瓶喂养会产生过度喂养的可能性。该项目的总体目标是确定防止婴儿期过度喂养的策略。一个目的是评估允许婴儿更好地控制从奶瓶喂养时消耗的量对摄入量的影响。这将通过使用一种新型乳头来实现，该乳头（功能上）模仿人类乳房的乳头，并允许婴儿自我调节乳汁流量。第二个目的是评估父母喂养方式与婴儿摄入量之间的关系。在研究的一组中，配方奶喂养的婴儿将被随机分配使用新型奶嘴或传统奶嘴。我们假设a）与随机使用常规奶嘴的婴儿相比，随机使用新型奶嘴喂养的婴儿每次喂养的摄入量较低，以及B）与非专制喂养方式的父母的儿童相比，专制喂养方式的父母的婴儿每次喂养的配方食品摄入量较高。其他结果包括24小时摄入量，婴儿体重增加，和婴儿烦躁。研究的另一组将在母乳喂养和奶瓶喂养的婴儿中进行。在该群组中，我们将a）比较乳房处的人乳摄入量与通过奶瓶喂养的挤出的人乳摄入量，B）评估当使用新型奶嘴与常规奶嘴相比时通过奶瓶喂养的人乳摄入量是否不同，以及c）检查父母喂养方式是否与婴儿摄入量相关。我们假设，母乳喂养时每次喂养的摄入量低于奶瓶喂养时，使用新型奶嘴时也低于传统奶嘴，母乳喂养婴儿的摄入量与父母的喂养方式无关。计划在前3个月内使用奶瓶喂养婴儿的母亲将在出院前从加州大学戴维斯医学中心的产科病房招募母乳或配方奶粉。婴儿将被随机分配使用新型奶嘴或传统奶嘴，并向母亲提供奶瓶和奶嘴。在整个研究期间，将每两周与母亲保持一次联系。在两个时间点，即婴儿3个月和4个月大时，母亲将完成48小时婴儿牛奶/配方奶粉摄入量的称重记录（包括所有母乳喂养前后的测试称重）。研究助理将测量婴儿的体重和身长，并进行退出访谈，以评估照顾者的喂养方式和他们对分配给他们的乳头的看法，以及他们的婴儿的喂养模式和生长。目标样本量为110名配方奶粉喂养（或混合喂养）婴儿和110名仅母乳喂养的婴儿（约4个月）。研究结果将为配方奶喂养和母乳喂养婴儿之间摄入量差异的原因提供重要证据，这对于设计有效的干预措施以减少婴儿期过度喂养和随后的儿童肥胖至关重要。儿童肥胖在美国已经达到了流行病的程度，鉴于四分之一的2-5岁儿童超重或肥胖，显然需要在生命早期进行预防。婴儿时期的过度喂养无疑会导致儿童肥胖，但导致过度喂养的因素还不清楚。这项研究将促进我们对影响婴儿摄入量的行为因素的理解，从而促进预防儿童肥胖的有效工具和策略的发展。

DESCRIPTION (provided by applicant): Prevention of Overfeeding During Infancy This application addresses broad Challenge Area (01) Behavior, Behavioral Change, and Prevention and specific Challenge Topic, 01-DK-102: Discovery of Behavioral Mechanisms Relevant to Obesity. It is becoming increasingly evident that prevention of child obesity must begin very early in life, as the prevalence of child overweight in the U.S. in the past 20 years has increased even in the youngest age groups. One of the key risk factors for later obesity is a rapid rate of weight gain during infancy; related behavioral factors are parenting styles and associated infant feeding practices. Overfeeding of infants, particularly those who are bottle-fed, presumably contributes to rapid weight gain, but there is little information on how to effectively address this issue. It is well-documented that formula-fed infants consume more energy and gain more weight than breastfed infants, even during the first few months of life. Furthermore, breastfed infants have a lower risk of developing child obesity, although the mechanisms for this remain unclear. One potential mechanism is that being fed from a bottle may encourage excessive intake. Infants who feed at the breast are able to self-regulate intake based on internal satiety cues, but bottle- feeding creates the possibility of overfeeding. The overall goal of this project is to identify strategies to prevent overfeeding during infancy. One objective is to evaluate the impact on intake of allowing the infant greater control over the amount consumed when feeding from a bottle. This will be accomplished via the use of a novel nipple that mimics (functionally) the nipple of a human breast and allows the infant to self-regulate milk flow. The second objective is to evaluate the relationship between parental feeding styles and infant intake. In one arm of the study, formula-fed infants will be randomly assigned to use the novel nipple or a conventional nipple. We hypothesize that a) infants randomized to be fed with the novel nipple will have a lower intake per feed compared to infants randomized to use a conventional nipple, and b) infants of parents with an authoritarian feeding style will have a higher intake of formula per feed compared with children of parents with non- authoritarian feeding styles. Additional outcomes include 24-h intake, infant weight gain, and caregiver-reported infant fussiness. The other arm of the study will be conducted with infants who are fed human milk both at the breast and with a bottle. In that cohort, we will a) compare intake of human milk at the breast to intake of expressed human milk fed by bottle, b) evaluate whether the intake of human milk fed by bottle is different when using the novel nipple compared to a conventional nipple, and c) examine whether parental feeding style is related to infant intake. We hypothesize that intake per feed will be lower when fed at the breast than when fed by bottle and also lower when using the novel nipple compared to a conventional nipple, and that intake of human milk-fed infants is not related to parental feeding style. Mothers who plan to use a bottle within the first 3 months to feed their infants either breast milk or formula will be recruited before discharge from the maternity ward of the University of California, Davis Medical Center. Infants will be randomized to the novel nipple or the conventional nipple, and a supply of bottles and nipples will be provided to the mother. Biweekly contact will be maintained with the mother throughout the study. At two time points, when the baby is 3 and 4 months old, the mother will complete a 48-hour weighed record of infant milk/formula intake (including test-weighing before and after all breast feeds). A research assistant will measure the infant's weight and length, and conduct an exit interview to evaluate caregivers' feeding style and their perceptions of the nipple to which they were assigned and their infant's feeding patterns and growth. The target sample size is 110 formula-fed (or mixed- fed) infants and 110 infants fed exclusively breast milk at ~ 4 mo. The results of the study will provide important evidence regarding the reasons for the difference in intake between formula-fed and breastfed infants, which is critical for designing effective interventions to reduce overfeeding during infancy and subsequent child obesity. Childhood obesity has reached epidemic proportions in the U.S., and the need for prevention very early in life is evident given that one-fourth of children aged 2-5 years are overweight or obese. Overfeeding during infancy undoubtedly contributes to child obesity, but the factors leading to overfeeding are not well understood. The proposed study will advance our understanding of the behavioral factors affecting infant intake, thereby facilitating the development of effective tools and strategies for prevention of child obesity.