Maybe check out r/ketoscience for more evidence based responses? They have a searchable database. I have done 120 hour water fasts and published an abstract on results. Each time I did a fast, I regularly dipped into hypoglycaemic territory but was asymptomatic. I am not diabetic and did strictly water fasting. I am also not a doctor so would not advise anyone to do anything here but my theory is that medical reference ranges are maybe more valuable because they are based on individuals following a standard American diet, and less meaningful if you are on a ketogenic diet or are fasting.