INS and Insulin resistance: After 16 weeks on a high-fat diet, when the inter-strain difference in %intraabdominal and %subcutaneous fat was no longer noticeable, insulin sensitivity assessed by a homeostasis model assessment of insulin resistance (HOMA-IR) was still significantly better in Cdkal1−/− mice (P<0.05, n = 5 for each strain) (Figure 2C).