Health Column
2-Hour Post-Meal Glucose of 140 and 200: When and How to Measure
Post-meal blood glucose shows how much your blood glucose rises and falls after you eat. Because it catches changes that fasting glucose alone can easily miss, it is looked at together with fasting glucose when assessing prediabetes.
Reference values (75 g oral glucose tolerance test)
| 2-hour blood glucose | Category |
|---|---|
| Below 140 mg/dL | Normal |
| 140 – 199 mg/dL | Impaired glucose tolerance (prediabetes) |
| 200 mg/dL or higher | Diagnostic criterion for diabetes |
KDCA National Health Information Portal, "Diabetes." In an oral glucose tolerance test, you drink 75 g of glucose at a medical facility, and your blood glucose is measured 2 hours later.
The "2 hours" when you measure at home
When you check post-meal blood glucose with a home blood glucose meter, measure 2 hours after the time you started eating. Not the time you finished the meal. Measuring by the same standard lets you compare from day to day.
The 140 and 200 criteria in the table above are for the oral glucose tolerance test, in which you drink 75 g of glucose at a medical facility. Values from a home meter after an ordinary meal vary with what and how much you ate, so don't apply them directly as diagnostic criteria; treat them as reference values for watching changes.
Talk to your health care provider if:
- Your 2-hour post-meal blood glucose repeatedly comes out at 140 or higher
- Your fasting glucose is normal but your HbA1c is 5.7% or higher
- You also have symptoms such as severe sleepiness or thirst after meals
- KDCA National Health Information Portal, "Diabetes"