Individual Differences in Children's Susceptibility to Overeating

描述(申请人提供)：儿童和青少年肥胖症的患病率已达到17%的历史最高水平。迫切需要更好地了解控制儿童食欲和饮食的行为机制，并确定在目前肥胖的食物环境中最容易暴饮暴食的儿童。肥胖症环境为人们提供了方便地获得大量美味、高能量食物的途径。食物的份量已被确定为成人和儿童能量摄入量的重要决定因素。虽然在健康个体的不同群体中发现了份量效应，但一些证据表明，儿童对大份量食物的反应程度可能存在个体差异。例如，之前一项实验室研究的数据表明，超重和肥胖的儿童在获得大量食物时，可能特别容易暴饮暴食。此外，食物份量对摄入量的影响大小也可能取决于儿童对食物的强化(或奖励)程度。食物的相对强化价值可能会与环境因素相互作用，例如食物的份量大小，从而在有大量美味的、能量密集的食物时影响儿童的能量摄入。这项研究的主要目的是比较增加一餐中所有食物和饮料的份量对正常体重和肥胖儿童能量摄入的影响。第二个目标是测试那些认为食物相对于吸引人的非食物替代品非常有补充性的儿童，是否会表现出比那些认为食物不那么有补充性的儿童在应对食物份量增加时能量摄入的显著增加。拟议的研究还将审查母婴喂养做法，如使用食物作为奖励，是否与食物在儿童中的相对强化价值有关。以前的研究已经确定了儿童能量摄入量的重要决定因素。在自由生活的条件下，环境因素与个人体重过度增加的倾向相互作用，从而影响饮食行为。通过同时检查环境影响和个体水平对暴食的易感性，我们或许能够识别出当单独检查这些决定因素中的任何一个时，可能被掩盖的暴食风险因素。这项拟议的研究将扩展之前的发现，以测试环境因素，如食物分量大小，可能如何与体重状况或食物强化的个体差异相互作用，影响儿童的能量摄入。这些数据将转化为制定预防和治疗儿童肥胖症的饮食和环境战略。 公共卫生相关性：为了制定有效的策略来预防和治疗儿童肥胖，迫切需要确定促进儿童暴饮暴食的可改变的饮食特征和环境因素。这项拟议的研究将阐明儿童的体重状况和食物的相对强化价值如何与食物环境的各个方面(食物份量)相互作用，以影响能量摄入。

DESCRIPTION (provided by applicant): The prevalence of childhood and adolescent obesity has reached an all-time high of 17%. There is a pressing need to better understand the behavioral mechanisms that control appetite and eating in children and to identify children who are most susceptible to overeating in the current obesogenic food environment. Obesogenic environments offer convenient access to large portions of palatable, energy-dense foods. The portion size of foods has been identified as an important determinant of energy intake in adults and children. While portion size effects have been found in heterogenous groups of healthy individuals, some evidence points to possible individual differences in the magnitude of children's responsiveness to large food portions. For example, data from a previous laboratory study suggest that overweight and obese children may be particularly vulnerable to overeating when presented with large food portions. Further, the magnitude of a portion size effect on intake may also depend on how reinforcing (or rewarding) children find food to be. It is possible that the relative reinforcing value of food may interact with environmental cues, such as the portion size of food, to affect children's energy intake when large portions of palatable, energy-dense foods are available. The primary aim of this study is to compare the effects of increasing the portion size of all foods and beverages served at a meal on energy intake in normal-weight and obese children. A second aim is to test if children who find food very reinforcing relative to an appealing nonfood alternative will show a significantly greater increase in energy intake in response to increasing portion sizes than will children who find food less reinforcing. The proposed study will also examine if maternal child feeding practices, such as using food as a reward, is associated with the relative reinforcing value of food in children. Previous studies have identified important determinants of energy intake in children. Under free-living conditions, environmental factors interact with individual predispositions to excessive weight gain to affect eating behavior. By examining environmental influences and individual-level susceptibility to overeating together, we may be able to identify risk factors for overeating that may be obscured when either one of these determinants is examined in isolation. The proposed study will extend previous findings to test how environmental factors, such as food portion size, may interact with individual differences in weight status or food reinforcement to affect energy intake in children. These data will translate to the development of dietary and environmental strategies for the prevention and treatment of childhood obesity. PUBLIC HEALTH RELEVANCE: In order to develop effective strategies to prevent and treat childhood obesity, there is a pressing need to identify modifiable eating traits and environmental factors which promote overeating in children. The proposed study will elucidate how children's weight status and relative reinforcing value of food may interact with aspects of the food environment (portion size) to affect energy intake.