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

描述（由申请人提供）：最近超重和肥胖患病率的显著增加暗示了这些问题的病因学中的行为因素，因此，提出了干预策略。目前的建议假设这一趋势部分归因于能量产生饮料的消费量增加，因为它们的消费量与BMI趋势一致，它们在饮食中的纳入或排除导致可预测的体重变化，它们现在占人口每日能量的20%以上，并且它们引起的食欲和饮食反应比半固体或固体食物弱。提出了四项人类研究，以对比对选定的摄食前（例如，认知、口腔感觉、咀嚼）对流体和固体食物形式的摄取的影响。早期的研究表明，食物的预期能量含量比它们的真实能量含量更能预测它们对食欲的影响，而流变学特性会影响这种预期。研究1将通过在摄入之前和之后操纵食物的预期和实际流变学特性，探索预期的饱腹感效应、GI通过时间、肠道激素分泌和对摄入匹配的液体和固体食物形式的血糖反应。据报道，大量营养素对食欲的影响是分层的，但在液体中似乎不太可预测。研究2将监测对营养成分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、GI转运、肠道激素分泌和血糖反应具有独立和协同作用，因此将在控制咀嚼活动并结合饮酒后测量这些结果。研究4将使用液体和固体饮食刺激来检查头相反应对餐后葡萄糖、胰岛素和选定的肠肽浓度的作用。此外，还将测试学习在这些应对措施中的作用。越来越多的证据表明，奖励系统可能会推翻自我平衡的食欲线索在调节摄食。所有的试验都将对比瘦个体和肥胖个体的结果，以确定后者能量平衡的调节机制是否不那么精确，特别是对于饮料。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。公共卫生相关性：甜菜碱占每日能量摄入量的20%以上。因为它们具有低饱腹感值，并且仅引起弱的补偿性饮食反应，所以它们与体重增加和肥胖有关。更好地理解饮料和其他食物形式对能量平衡的影响不同的机制，以支持或挑战将饮料摄入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。该项目将探讨是否摄入前因素（例如，认知、口腔感觉线索、咀嚼）不同地引起食欲、饮食和生理（例如，在精瘦和肥胖个体中涉及能量平衡的GI运输、肠道内分泌分泌、消化道反应。

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.