Pre-Ingestive Influences on Solid and Fluid Food Intake in Lean and Obease Adults

描述(由申请人提供)：最近超重和肥胖率的显著上升表明，行为因素与这些问题的病因有关，因此，建议了干预策略。目前的提案假设，这一趋势部分归因于高能量饮料的消费增加，因为它们的消费量与BMI趋势同步上升，它们被纳入或被排除在饮食中会导致可预见的体重变化，它们现在贡献了人口日常能量的20%以上，它们引起的食欲和饮食反应比半固体或固体食物更弱。建议进行四项人体研究，以对比一系列对选定的摄食前(例如，认知、口腔感觉、咀嚼)对液体和固体食物摄取的影响的食欲和生理反应。早期的研究表明，食物的预期能量含量能更好地预测它们对食欲的影响，而不是它们的真实能量含量和流变性影响这一预期。研究1将通过控制食物在摄入之前和之后的预期和实际流变性，来探索摄入匹配的液体和固体食物形式时预期的饱腹感效应、胃肠道通过时间、肠道激素分泌和血糖反应。据报道，大量营养素对食欲的影响是有继承性的，但在流质中似乎更难预测。研究2将监测人们对营养素含量不同的液体和固体食物的食欲反应，以澄清这一问题。由于假设咀嚼对食欲、胃肠道转运、肠道激素分泌和血糖反应有独立和协同的影响，这些结果将在受控的咀嚼活动和饮酒后进行测量。研究4将使用流质和固体饮食刺激，研究头位相反应对餐后血糖、胰岛素和选定肠肽浓度的作用。此外，还将测试学习在这些反应中的作用。越来越多的证据表明，在调节摄食时，奖励系统可能会超过动态平衡的食欲提示。所有试验都将对比瘦人和肥胖者的研究结果，以确定在后一组人中，能量平衡的调节机制是否可能不那么精确，特别是对饮料。这些发现应该有助于制定饮食建议和产品，以解决超重/肥胖问题。与公共健康相关：饮料占每日能量摄入量的20%以上。因为它们的饱腹感低，只会引起微弱的补偿性饮食反应，所以它们与体重增加和肥胖有关。提高对饮料和其他食物形式对能量平衡影响的不同机制的理解，有助于支持或质疑将饮料摄入量与肥胖联系起来的行为数据，并制定有效的体重管理干预策略。这个项目将探索与饮料和固体食物摄入相关的摄食前因素(例如，认知、味觉提示、咀嚼)是否会在不同的情况下引发食欲、饮食和生理(例如，胃肠道转运、肠道内分泌、血糖)反应，参与瘦身和肥胖者的能量平衡。

DESCRIPTION (provided by applicant): The marked recent increase in overweight and obesity prevalence implicates behavioral factors in the etiology of these problems and, as a consequence, suggests strategies for intervention. The present proposal hypothesizes the trend is attributable, in part, to increasing consumption of energy-yielding beverages since their consumption has risen in concert with BMI trends, their inclusion or exclusion from diets leads to predictable weight changes, they now contribute over 20% of daily energy in the population and they elicit weaker appetitive and dietary responses than semi-solid or solid foods. Four human studies are proposed to contrast an array of appetitive and physiological responses to selected pre-ingestive (e.g., cognitive, orosensory, masticatory) influences on ingestion of fluid and solid food forms. Early work indicated the expected energy content of foods better predicted their impact on appetite than their true energy content and rheological properties influence this expectation. Study 1 will explore the anticipated satiety effects, GI transit time, gut hormone secretion and glycemic response to ingestion of matched fluid and solid food forms by manipulating the expected and actual rheological properties of the foods prior to and following ingestion. A heirarchy of appetitive effects have been reported for the macronutrients, but appear less predictable in fluids. Study 2 will monitor appetitive responses to fluid and solid foods varying in nutrient content to clarify this issue. Because of hypothesized independent and synergistic effects of mastication on appetite, GI transit, gut hormone secretion and glycemic responses, these outcomes will be measured following controlled masticatory activity in conjunction with drinking. Study 4 will examine the role of cephalic phase responses on post-prandial glucose, insulin and selected gut peptide concentrations using fluid and solid dietary stimuli. In addition, the role of learning in these responses will be tested. Increasing evidence suggests that the reward system may override homeostatic appetitive cues in the regulation of feeding. All trials will contrast findings from lean and obese individuals to determine whether the regulatory mechanisms for energy balance may be less precise, especially for beverages, in the latter group. The findings should aid development of dietary recommendations and products to address the problems of overweight/obesity. PUBLIC HEALTH RELEVANCE: Beverages contribute over 20% of daily energy intake. Because they have low satiety value and elicit only weak compensatory dietary responses, they have been implicated in weight gain and obesity. An improved understanding of the mechanisms by which beverages and other food forms differ in their impact on energy balance is warranted to support or challenge the behavioral data linking beverage intake to obesity and to develop effective intervention strategies for weight management. This project will explore whether pre-ingestive factors (e.g., cognition, orosensory cues, mastication) associated with beverage versus solid food ingestion differentially elicit appetitive, dietary and physiological (e.g., GI transit, gut endocrine secretion, glycemia) responses involved in energy balance in lean and obese individuals.