Post-meal glucose ("postprandial") is one of the earliest and most useful signals of metabolic health. Knowing the target ranges helps you read your meter or CGM without panic.
Target ranges (2 hours after a meal)
| Group | Target |
|---|---|
| Healthy adult | Under 140 mg/dL |
| Prediabetes | 140-199 mg/dL |
| Diabetes | 200+ mg/dL |
The ADA's diabetes diagnostic threshold uses a standardized 75g glucose drink, but a regular meal that pushes you over 200 consistently is worth investigating.
At 1 hour
For healthy adults, peak glucose typically lands 45-90 minutes after eating, usually in the 120-150 mg/dL range. Peaks above 180 mg/dL more than occasionally are an early sign of insulin resistance.
What pushes the number up
- Larger portions of fast carbs (white rice, bread, juice)
- Eating fast and without protein/fat to slow digestion
- Stress (cortisol blocks insulin)
- Poor sleep the night before
- Sedentary day (walking after meals lowers peak by 20-30%)
When to call your doctor
- Fasting glucose over 100 mg/dL on multiple days
- Post-meal glucose over 180 mg/dL regularly
- Hemoglobin A1c over 5.7%
- New thirst, frequent urination, or unexplained weight loss
Bottom line
A short spike to 140-160 after a treat is normal. Sustained highs or wide swings are worth a conversation with your doctor — early is better.