The Snack Study

 描述(由申请人提供)：现有研究支持宫内环境在改变后代肥胖风险中的作用。孕妇肥胖和相对较高的葡萄糖浓度是下一代肥胖的两个常见预测指标，可能是通过胎盘向发育中的胎儿输送多余的燃料，进而可能以一种促进未来超重增加的方式来调节胎儿的新陈代谢。尽管以前曾尝试过一些改善母婴结局的生活方式干预措施，但效果往往充其量也是有限的。此外，很少有研究被证明对低收入的非裔美国女性有效，她们有很高的肥胖遗传给后代的风险。PI(K01DK090126；刚果民主共和国飞行员奖)之前进行的研究发现，在怀孕后期肥胖的非裔美国女性中，深夜食用高血糖指数(GI)食物非常普遍。与现有文献描述的倒班工作和深夜进食的不良代谢后果相一致，这种每日摄入模式与母亲的葡萄糖耐量降低有关，而婴儿的一些结果本身与未来的肥胖有关。这项研究的总体目标是通过研究开发一种干预措施的可行性来跟踪这项先前的研究，以减少肥胖的非裔美国女性深夜高GI食物和饮料的摄入量，以提高母亲的葡萄糖耐量，减少妊娠后期胎儿的过度生长。这一目标将通过两个阶段的研究来实现。首先，将对肥胖的非裔美国孕妇进行焦点小组，以确定深夜食用高GI食物的原因、改变这一行为的障碍，以及对减少深夜高GI摄入的干预的看法。其次，将使用随机对照试验(RCT)设计来检验在怀孕后期进行干预以减少肥胖女性深夜高GI消费的可行性。该干预措施将提供低GI替代方案，以取代目标人群通常消费的高GI食品和饮料。在干预期间，将测量自由生活血糖变异性、葡萄糖耐量和胎儿腹部发育的变化，并与对照组(即标准护理组)的妇女进行比较。在这项研究的结论中，预计将获得足够的初步数据，用来提供更大和更全面的随机对照试验。此外，这项研究将通过提供一个机会，从实验上检验在宫内暴露于母体肥胖和/或高糖浓度后肥胖发展的生物行为机制，从而支持PI向独立性的转变。

 DESCRIPTION (provided by applicant): Existing research supports a role for the intrauterine environment in modifying risk for obesity in offspring. Maternal obesity and relatively high glucose concentrations are two commonly cited predictors of obesity in the next generation, potentially via the delivery of excess fuel across the placenta to the developing fetus, which in turn, may program fetal metabolism in a manner that promotes excess weight gain in the future. Although a number of lifestyle interventions to improve maternal and infant outcomes have previously been attempted, results are often modest at best. Furthermore, few studies have proved to be efficacious among low income African American women who have high risk for the transmission of obesity to future generations. Research previously conducted by the PI (K01DK090126; DRC pilot award), has discovered that late-night consumption of high glycemic index (GI) foods is very prevalent in late pregnancy among African American women who are obese. Consistent with the existing literature describing adverse metabolic consequences of shift-work and late-night eating, this diurnal pattern of intake was associated with reduced glucose tolerance in the mothers, and a number of infant outcomes that are themselves associated with future obesity. The overall goal of this study is to follow-up this previous research by examining the feasibility of developing an intervention to reduce late-night intake of high-GI foods and beverages among obese African American women, in order to improve maternal glucose tolerance and reduce excess fetal growth in late gestation. This goal will be achieved with a two-phase study. First, focus groups will be conducted with pregnant African American women who are obese, in order to identify reasons for late-night consumption of high-GI foods, barriers against changing this behavior, and perceptions of an intervention to reduce late-night high-GI intake. Second, a randomized control trial (RCT) design will be used to examine the feasibility of conducting an intervention to reduce late-night high-GI consumption among obese women during the third trimester. The intervention will provide lower-GI alternatives to replace the high-GI foods and beverages that are typically consumed by the target population. Changes in free-living glycemic variability, glucose tolerance, and fetal abdominal growth, during the intervention will be measured and compared to those of women in a control (i.e. standard care) group. At the conclusion of this study, it is anticipated that suffiient preliminary data will have been obtained with which to inform a larger and more comprehensive RCT. Furthermore, this study will support the PI's transition to independence by providing an opportunity to experimentally examine the biobehavioral mechanisms underlying the development of obesity following intrauterine exposure to maternal obesity and/or high glucose concentrations.