Understanding Blood Glucose
Normal blood glucose means a fasting blood glucose below 100 mg/dL and an HbA1c below 5.7%. A fasting blood glucose of 100–125 or an HbA1c of 5.7–6.4% is prediabetes. A fasting blood glucose of 126 or higher or an HbA1c of 6.5% or higher meets the diagnostic criteria for diabetes (KDCA National Health Information Portal). In Korea, 41.1% of adults aged 30 and older have prediabetes (Korean Diabetes Association 2024).
Understanding Blood Glucose
Blood glucose is the concentration of glucose in your blood. After you eat, blood glucose rises. Then insulin released from the pancreas moves glucose into your cells, and blood glucose comes back down. When this regulation does not work well and blood glucose stays high, it is diabetes.
Between normal and diabetes is prediabetes. It has almost no symptoms and is easy to miss, but it is also the stage when lifestyle management has the greatest effect.
Blood glucose reference values (Korean criteria)
| Category | Fasting blood glucose | HbA1c | 2 hours after 75 g oral glucose tolerance test |
|---|---|---|---|
| Normal | Under 100 mg/dL | Under 5.7% | Under 140 mg/dL |
| Prediabetes | 100–125 mg/dL (impaired fasting glucose) | 5.7–6.4% | 140–199 mg/dL (impaired glucose tolerance) |
| Diabetes | 126 mg/dL or higher | 6.5% or higher | 200 mg/dL or higher |
Blood glucose in numbers
When to get a blood glucose test
- Your fasting blood glucose was 100 mg/dL or higher at a recent health checkup
- Your waist circumference is 90 cm or more for men, or 85 cm or more for women (Korean criteria)
- Someone in your family has diabetes
- You drink a lot of water, urinate often, and lose weight for no reason
Partner company product
ONDAM BIO ‘SANBIDAM Premium’
For people who pay attention to blood glucose after meals along with managing their diet, we introduce a health functional food from a partner company. Each daily bottle (50 ml) contains resistant maltodextrin, a water-soluble dietary fiber, and a Cornus extract complex made from Korean-grown Cornus fruit and Ribes fasciculatum leaf blended 7 to 3.
- Resistant maltodextrin 10,000 mg — may help suppress the rise in blood glucose after meals · may help improve blood triglyceride levels · may help support regular bowel movements
- Cornus extract complex 1,600 mg — may help reduce body fat (MFDS individually approved functional ingredient No. 2022-26)
This is a product of an Association partner company and does not mean certification or endorsement by the Association. Health functional foods are not medicines for preventing or treating disease. If you are being treated for diabetes or taking medication, talk to your health care provider.
- KDCA National Health Information Portal, “Diabetes”
- Korean Diabetes Association, Diabetes Fact Sheets in Korea 2024 (Diabetes Metab J 2025;49:24-33), based on Korea National Health and Nutrition Examination Survey (KNHANES) 2021–2022