Pre-diabetes in Subject With Impaired Fasting Glucose (IFG) and Impaired Glucose Tolerance (IGT)

This study is investigating pre-diabetes — specifically two types called impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) — to better understand how the body handles blood sugar before full diabetes develops. Healthy volunteers without pre-diabetes are also needed as a comparison group. **You may be eligible if...** - You are between 18 and 65 years old (male or female) - You have pre-diabetes (either IFG or IGT) OR you are a healthy control with normal blood sugar levels - Your BMI is between 24 and 40 - Your weight has been stable (within 4 lbs) for the past 3 months - You have no major organ disease based on physical exam or lab tests **You may NOT be eligible if...** - You have fully developed Type 1 or Type 2 diabetes - You have significant heart, kidney, liver, or other organ problems - You take certain medications that affect blood sugar - You are pregnant or planning to become pregnant - Your weight has changed significantly in the past 3 months Talk to your doctor to see if this trial is right for you.