INS and Insulin resistance: However, fasting blood glucose levels were elevated (Fig. 1b), glucose tolerance was reduced as assayed by the glucose tolerance test (GTT) (Fig. 1c, Supplementary Fig. 1c), insulin tolerance was reduced as assayed by the insulin tolerance test (ITT) (Fig. 1d), blood insulin levels were increased (Fig. 1e), and the homeostasis model assessment of insulin resistance (HOMA-IR), indicators of insulin resistance, and T2D25 (Fig. 1f) were induced by phenylalanine-rich chow feeding.