Whole-fat dairy consumption (whole milk, 2% milk, cheese, butter, and ice cream) most strongly associated with higher trans-9 C16:1. trans-9 C16:1 associated with higher HDL cholesterol (1.9%, P = 0.04), lower TAG (−19%, P < 0.001), lower total cholesterol to HDL cholesterol ratio (−4.7%, P < 0.001), lower CRP (−13.8%, P = 0.05), lower insulin resistance (−16.7%, P < 0.001), and lower incidence of T2D (HR, 0.38; 95%CI, 0.24–0.62; P < 0.001). This evidence concerns the gene CRP and Insulin resistance.