LATITUDE WITHIN AN NCEP STEP I DIET--AN OPTIMAL DIET

这项研究的目的是检验NCEP/AHA Step One饮食对降低冠心病(CHD)风险的潜在公共健康影响目前是否被低估了，因为过度强调避免脂肪和胆固醇，而低估了包括植物性食品。植物性食品中的大量饮食因素与各种CHD风险因素的减少有关。然而，食品行业在过去十年里生产了数千种新的“减脂”食品，现在已经有可能效仿Step One Diet，以低脂商业食品(通常是高卡路里)为基础，而不是植物性食品。我们将设计两种饮食，都符合NCEP/AHA第一步饮食指南，并在总脂肪、饱和脂肪、单不饱和脂肪、多不饱和脂肪、胆固醇、蛋白质和总碳水化合物方面匹配。一种饮食将包括很大比例的植物性食物，并将相对较高的植物蛋白、精氨酸复合碳水化合物、可溶性和不溶性纤维、维生素E、C和叶酸、类胡萝卜素、植物类固醇、植物雌激素、类黄素、大蒜素和皂苷的含量(NCEP-Plus)。另一种饮食将包括很大比例的商业可获得的减脂产品，并将相对较高的动物蛋白，简单碳水化合物和反式脂肪酸(NCEP-LOW)。在一项采用平行设计的临床试验中，100名低密度脂蛋白-胆固醇(LDL-C 130-190 mg/dL)中度升高的成年人将被随机分成两种饮食之一，为期四周。我们会提供所有的餐食。这两种研究饲料的组成将通过化学分析来确定。主要研究终点将包括空腹血清低密度脂蛋白-C、胰岛素和同型半胱氨酸水平、单核细胞黏附和内皮功能。我们的目的是研究关注避免脂肪和胆固醇而不是包括植物性食物是否会导致低估NCEP/AHA第一步饮食的潜在健康益处，并确定通过利用当前的营养知识设计“最佳”整体饮食可以在总体CHD风险因素方面实现的有利变化的幅度。

The objective of the study is to examine whether the potential public health impact on coronary heart disease (CHD) risk reduction of an NCEP/AHA Step One Diet may currently be underestimated because of an overemphasis on the avoidance of fat and cholesterol and an underemphasis on the inclusion of plant-based foods. A large number of dietary factors in plant based foods have been linked to the reduction of various CHD risk factors. However, the food industry's production of thousands of new "reduced-fat" food products over the last decade has now made it possible to follow a Step One Diet with a foundation in low-fat commercial foods (that are often high in calories) rather than plant-based foods. We will design two diets that both meet NCEP/AHA Step One Diet guidelines and are matched on total fat, saturated fat, monounsaturated fat, polyunsaturated fat, cholesterol, protein and total carboyhydrate. One diet will include a large proportion of plant- based foods, and will be relatively higher in content of plant protein, arginine complex carbohydrates, soluble and insoluble fiber, Vitamins E, C and folate, carotenoids,phytosterols, phytoestrogens, flavonoids, allicin and saponins (NCEP-Plus). The other diet will include a large proportion of commercially available reduced-fat products and will be relatively higher in animal protein, simple carbohydrates and trans fatty acids (NCEP-Low). In a clinical trial using a parallel design, 100 adults with moderately elevated LDL-cholesterol (LDL-C 130-190 mg/dL) will be randomized to one of the two diets for four weeks. All meals will be provided. The composition of the two study diets will be determined by chemical analysis. The primary study endpoints will include fasting serum levels of LDL-C, insulin and homocysteine, monocyte adhesion, and endothelial function. Our intentions are to examine whether a focus on avoiding fat and cholesterol rather than including plant-based food result in underestimating the potential health benefits of an NCEP/AHA Step One Diet, and to determine the magnitude of favorable changes in an overall CHD risk factor profile that can be achieved by using current nutrition knowledge to design an "optimal" overall diet.