One is that you're supposed to eat a variety of foods and then the foods are put into different sized triangles here, depending on how much of them you should be eating.

一是你得吃多种不同的食物,各种食物也被分划在不同大小的三角形中,每个三角形的大小取决于你该吃多少

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选