膳食结构是指膳食中各类食物的数量及其在膳食中所占的比重 ,与食物生产结构和饮食习惯密切相关。近年来营养学界对单一食物或营养素和疾病的关系做了大量研究 ,而疾病的发生主要与整体膳食结构相关。由于膳食结构评价指标很多 ,解释变得相当困难。主成分分析是多元统计的一种 Dietary structure refers to the amount of all kinds of food in the diet and its share in the diet, and the food production structure and eating habits are closely related. In recent years, the nutrition community has done a great deal of research on the relationship between single food or nutrients and diseases, and the incidence of diseases is mainly related to the overall dietary structure. Due to the many indicators of dietary structure, interpretation becomes quite difficult. Principal component analysis is a kind of multivariate statistics