Dietary Variety vs Dietary Fat Effects on Energy Intake

描述(由申请人提供)：饮食模式和大量营养素组成在影响能量摄入和体重方面的相对重要性仍不确定。在这项研究中，我们建议调查饮食种类和饮食脂肪对成年人自愿能量摄入量的相对影响。具体地说，我们将量化和比较美国人饮食中不同种类和脂肪摄入量的典型范围(基于美国全国调查数据)对自愿能量摄入的影响。要检验的主要假设是：(1)当其他已知影响能量摄入量的饮食因素(包括大量营养素组成、适口性和其他食物的种类)保持不变时，提供的主菜/配菜/小吃/甜点种类的增加将以剂量-反应方式显著增加自愿能量摄入量；(2)饮食种类和饮食脂肪对能量摄入量的单独影响将是相似的。健康、体重稳定的男性和女性(n=96，年龄18-45岁，体重指数20-35公斤/平方米)将被招募参加一项为期39天的研究，其中提供食物。三种水平的主菜/配菜/零食/甜点将在三种水平的饮食脂肪摄入量中每一种提供，这些饮食操作对自愿能量摄入量的相对影响将被量化，而不考虑潜在的混杂饮食因素。受试者将被分配到体重指数匹配的三组中的一组，在三个13-d阶段的每一个阶段，每天将提供4、8或12个主菜/配菜/零食/甜点项目，在三个脂肪摄入量水平(能量的20%、35%或50%)中的一个。所有的饮食都将在适口性、纤维、蛋白质含量和其他食物的种类以及每种脂肪摄入量的能量密度方面进行匹配。将测量每日自愿能量摄入量，并通过测量24小时尿PABA和渗透压排泄率来监测饮食依从性。其他测量包括食物和膳食的适口性、饥饿感、进食欲望、饮食去抑制、能量消耗以及体重和成分。我们预计这项调查的结果将有助于更好地理解饮食模式和常量营养素组成在肥胖病因中的相对重要性，更具体地说，饮食变化和饮食脂肪在决定能量摄入量方面的相对重要性。最重要的是，这将有助于为改进关于减肥和预防成年后超重增加的饮食建议奠定基础。

DESCRIPTION (provided by applicant): The relative importance of dietary patterns vs. macronutrient composition in affecting energy intake and body weight remains uncertain. In this study we propose to investigate the relative effects of dietary variety versus dietary fat on voluntary energy intake in adults. Specifically, we will quantify and compare the effects of typical ranges of variety and fat intakes in the American diet (based on U.S. national survey data) on voluntary energy intake. The primary hypotheses to be tested are (1) an increasing availability of entree/side/snack/dessert variety offered will significantly increase voluntary energy intake in a dose-response fashion when other dietary factors known to influence energy intake are held constant (including macronutrient composition, palatability and variety of other food items); and (2) the separate effects of dietary variety and dietary fat on energy intake will be similar. Healthy, weight stable men and women (n=96, aged 18-45 y, BMI 20-35 kg/m2) will be recruited for a 39-d study in which food is provided. Three levels of entree/side/snack/dessert variety will be offered at each of three levels of dietary fat intake, and the relative effects of these dietary manipulations on voluntary energy intake, independent of potentially confounding dietary factors, will be quantified. Subjects will be assigned to one of three BMI-matched groups that will be offered either 4, 8 or 12 entree/side/snack/dessert items/d at one of three fat intake levels (20, 35, or 50 % of energy) in each of three 13-d phases. All diets will be matched for palatability, fiber, protein content, and the variety of other food items, and also for energy density at each fat intake level. Daily voluntary energy intake will be measured and dietary compliance monitored by using measurements of 24-h urinary PABA and osmolar excretion rates. Other measurements include food and meal palatability, hunger, desire to eat, dietary disinhibition, energy expenditure, and body weight and composition. We anticipate that the results of this investigation will lead to a greater understanding of the relative importance of eating patterns vs macronutrient composition in the etiology of obesity, and more specifically, dietary variety versus dietary fat in determining energy intake. Most importantly, it will help lay a foundation for improved dietary recommendations concerning weight loss and prevention of excess weight gain in adulthood.