Glucose Tolerance Test

How should I prepare for a glucose tolerance test?

A Answers (1)

  • AHealthwise answered

    Glucose tolerance diagnostic test

    To prepare for the glucose tolerance diagnostic test:

    • Eat a balanced diet that contains at least 150 grams (g) of carbohydrate per day for 3 days before the test. Fruits, breads, cereals, grains, rice, crackers and starchy vegetables such as potatoes, beans and corn are good sources of carbohydrate.
    • Do not eat, drink, smoke or exercise strenuously for at least 8 hours before your first blood sample is taken.
    • Tell your doctor about all prescription and nonprescription medicines you are taking. You may be instructed to stop taking certain medicines before the test.

    The glucose tolerance diagnostic test may take up to 4 hours. Since activity can interfere with test results, you will be asked to sit quietly during the entire test. Do not eat during the test. You may drink only water during this time.

    Talk to your doctor about any concerns you have regarding the need for the test, its risks or how it will be done.

    This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. To learn more visit

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