What are healthy blood sugar levels for a 40-year-old?

Fasting: 70-99 mg/dL (morning).

After meals: 140-180 mg/dL.

Hemoglobin A1c: Less than 5.7% (3-month average).

Random: Below 140 mg/dL.

Pre-exercise: 90-250 mg/dL.

Pre-bedtime: 90-150 mg/dL.

CGM: Typically 70-180 mg/dL (if using a continuous glucose monitor).