What is an optimal fasting glucose level?
The short answer
An optimal fasting glucose level is 70–90 mg/dL. Dr. Peter Attia puts the ceiling at 90. You can watch him say it below.
Most labs call fasting glucose high only above 99. So your report can call 95 normal while it sits above where he draws the line.
“I generally like to see the fasting glucose below 90 milligrams per deciliter, the fasting insulin below six.”
Where a number lands, and who said so
- under 70 mg/dL Most labs flag this as low
- 70–90 mg/dL The range Dr. Peter Attia draws
- 90–99 mg/dL Normal on most reports. Above optimal Dr. Peter Attia · 6:34 →
- over 99 mg/dL Most labs flag this as high
What fasting glucose measures
The sugar in your blood after a night without food.
It is the most direct look at how well your body clears sugar with no food in the system.
Checked against MedlinePlus — Blood Glucose Test.
One of the doctors we cite, on why it matters
“glucose causes microvascular disease the insulin causes macrovascular disease they're both bad you need to control both of them”
Common questions
What is an optimal fasting glucose level?
70–90 mg/dL, according to Dr. Peter Attia.
What is a normal fasting glucose level?
Most US labs print 70–99 mg/dL. Your report grades you against that range. It exists to catch disease, not to describe your best.
What does your fasting glucose number mean?
Under 70 mg/dL, your report marks it low. Between 70 and 99 it prints as normal. Over 99, your report marks it high. Where the people we follow draw their own line is above.
Is fasting glucose of 95 normal?
Your lab will call it normal. Dr. Peter Attia puts the ceiling at 90 mg/dL, so by that number it is high.
What does the fasting glucose test measure?
The sugar in your blood after a night without food. It is the most direct look at how well your body clears sugar with no food in the system.
Where does this number come from?
Dr. Peter Attia, on video. The link above jumps straight to that minute.