Final answer:
Testing for fasting plasma glucose (FPG) usually begins following a fast of at least 8 hours. Glucose tolerance tests can help identify diabetes mellitus by assessing an individual's ability to tolerate glucose. Normal fasting blood glucose levels are below 100.
Step-by-step explanation:
Testing for fasting plasma glucose (FPG) usually begins following a fast of at least 8 hours. A fasting blood glucose level below 100 is considered normal, between 100-125 is considered pre-diabetes, and above 125 is diagnosed as diabetes. Glucose tolerance tests are used to assess an individual's ability to tolerate glucose and identify diabetes mellitus. The test involves measuring blood glucose levels before and after consuming a specified amount of glucose over a period of time.