The gentlebirth.org website is provided courtesy of
Ronnie Falcao, LM MS, a homebirth midwife in Mountain View, CA

Diet Preparation for Three-Hour Glucose Tolerance Test

From Ambulatory Obstetrics by Winifred L. Star et al.

Your one-hour glucose-screening test was abnormal. You will need to schedule a three-hour glucose tolerance test with the clinical laboratory. A glucose tolerance test checks how well your body responds to sugar. This test must be scheduled at a time that allows you to follow the special three-day diet. Please call the lab to schedule your appointment.

In order to decrease the chance of a falsely abnormal test result; please follow the instructions below:
1. Continue to eat regular meals and all the foods you normally enjoy
2. For three days before the test you must include extra carbohydrates (at least 150 grams or more) in your daily food intake. To make sure you are eating enough carbohydrates you must choose extra foods.
3. Choose one item from List I and also an item from List 2. Eat these foods in addition to the usual foods you eat for three days before the test.
 
 

List 1	List 2
2 slices of bread	8 T. (4 0z.) raisins
2/3 cup of cooked rice	2 large apples
1 cup cooked noodles	2 small bananas
2 corn tortillas	16 oz. orange or apple juice

Example

Day one

Extra 2 slices of bread
16 oz. of apple juice

Day two

Extra 1 C. of noodles
16 oz. orange juice

Day three

Extra two bananas
2 corn tortillas

On the third day of your diet, eat nothing (not even toast) and drink nothing but sips of water after 10:00 p.m. and until the test is over.
Please arrive at the clinic lab no later than 8:30 a.m.
First a fasting blood sample will be drawn, then you will be given a sugsary liquid to drink.
Each hour after the drink, blood will be drawn. This will be done three times. It is important that the blood be drawn at exactly one-hour intervals, so please be available at the indicated times.
Please bring something to read or do while quietly sitting, until the test is over.
Do not eat, smoke or drink anything except water during the test. Sips of water should be taken only if you are very thirsty.
After the last blood sample has been drawn, you may leave the laboratory and have your lunch.
If you are unable to eat your usual diet, please inform your health care provider.
Maintain your usual activity level on the days preceding the test.

Source: Adapted with permission from the University of California, San Francisco, OB Clinic.