Dietary Variety vs Dietary Fat Effects on Energy Intake

描述（由申请方提供）：饮食模式与常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，我们建议调查的相对影响，膳食品种与膳食脂肪的自愿能量摄入的成年人。具体来说，我们将量化和比较美国饮食中典型的品种和脂肪摄入量范围（基于美国全国调查数据）对自愿能量摄入的影响。待检验的主要假设是：（1）当其他已知影响能量摄入的饮食因素保持不变时，提供的主菜/配菜/零食/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（包括大量营养素成分、适口性及其他食物种类）;（2）膳食种类和膳食脂肪对能量摄入的单独影响相似。将招募健康、体重稳定的男性和女性（n=96，年龄18-45岁，BMI 20-35 kg/m2）进行39天研究，其中提供食物。将在三个膳食脂肪摄入水平中的每一个水平上提供三个水平的主菜/配菜/零食/甜点品种，并且将量化这些饮食操作对自愿能量摄入的相对影响，而不依赖于潜在的混杂饮食因素。受试者将被分配到三个BMI匹配组中的一个，在三个13天阶段的每个阶段中，以三种脂肪摄入水平（20、35或50%的能量）之一每天提供4、8或12种主菜/配菜/零食/甜点。所有的饮食都将在适口性、纤维、蛋白质含量和其他食物种类以及每个脂肪摄入水平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和渗透压排泄率监测饮食依从性。其他测量包括食物和膳食适口性、饥饿感、进食欲望、饮食去抑制、能量消耗以及体重和组成。我们预计，这项调查的结果将导致更好地了解饮食模式与大量营养素组成在肥胖病因学中的相对重要性，更具体地说，饮食多样性与膳食脂肪在确定能量摄入方面的相对重要性。最重要的是，它将有助于为改善有关减肥和预防成年后体重过度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.