Of note, healthy NRs fed on the Hfib diet demonstrate a high abundance of G6Pase and PEPCK throughout the study, reflecting an overall enhanced hepatic glucose production that is likely advantageous in their native environment but which could be a risk factor for glucose intolerance when switching to a high-energy and high refined carbohydrate diet like Chow. The gene discussed is PCK2; the disease is Glucose intolerance.