Ask the Diabetes Educator Archive


I have impaired glucose tolerance. I'm finding that my blood sugar peaks about 2 hours and 10 min after the START of my meal. A diabetes educator told me to test 2 hours after the start of my meal, someone at the ADA told me to test about 15 min after the start of my meal. Who is correct? In my case it makes a big difference.


A mixed meal which includes carbohydrates will peak at one hour; most post meal blood tests are done two hours after the meal in non-pregnant cases. This is because, by two hours, all carbohydrates have completed the digestive process.

Testing 15 minutes at the start of the meal can be an indicator as to whether or not the first phase of insulin releasing is occurring; generally, this is impaired in diabetes. Humalog insulin was designed to mimic this first phase.

The usual testing patterns are premeal or one-two hours post meal. It is important to know how your meal intake affects your blood sugar. It is those momentary spikes of high blood sugars occurring throughout the day that create wear and tear on the nervous system. Ask your health practitioner as to when you should check, and what your blood sugar goals are.

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