Fasting GTT and carbohydrates in diet prior to test...?

I have to do the 2hr GTT next Thursday and just have a question.

Just wondering what the deal is with the GTT, and some people being asked to carb load (more than 150g carbs a day for 3 days leading up to the test) and some don't need to...?

Does is make a difference? I usually have a fairly high carb diet anyway (yes I know! Naughty!), but since getting the GCT results come back as high I have tried to cut back and eat lower carb/GI foods. Would this effect the results?

My midwife didn't say anything about changing my diet at all for the test, actually she's never asked anything about my diet at all, nor did the path lab, so I'm wondering if I should just eat like I had been or try to keep the carbs down?

My pathology lab gave me a special diet that I had to follow for the three days prior to the test. It had an amount of carbs to eat and at what times during the day. I think (pg brain) that I then had to fast prior to the test (8hrs) maybe and drink water only. I went in as soon as the lab opened at 8am and they did bloods and urine sample, then I drank the drink then did two more bts at hourly intervals, while still fasting. The girls in the lab checked up on me often as to how I was feeling, as the combination of the drink, high carb, fasting does make for quite an unwell feeling.

Maybe ring your pathology lab as ask them for the procedures, cause that is what I did, and mine sent me the diet sheet.

Good luck and I hope this one comes back more positive than the last one.

xo

I didnt do much diet change before the test, but I should have!! I was 0.1 over the norm and had to monitor my bloods for 3wks... I keep thinking if id cut out a few things the 3 days before I might have passed the stupid test! I was so upset about it all...

Anyway, my 3wks of testing was fine, no results higher than they should be and after the first week I was much more relaxed in my eating, getting away with lamingtons, milo etc...

It definitely caused me to take notice of what is in food, some things have a lot more sugar than you expect!

So I would try and go LOW GI for the 3 days before the test, and low sugar intake of course! There are foods that help fight your glucose level like liver, yeast (beer) and mushrooms

I went to the doctor and I no longer have to monitor my blood, they were just being careful because my result was a tad high!

Good Luck with the test... take a mag or suduko! Its a boring wait!

Hi Leasha

I had a diet to follow from the Path lab also for the long GTT test.

Heres a sample of the a diet for GTT an a pathology govt website to give you some ideas:
Diet For Oral Glucose Tolerance Test
Download: GTT factsheet (PDF File - 660k)

Authorised by the Director of Chemical Pathology Feb 2008.
Glucose Tolerance Test Instructions

You are to have an oral glucose tolerance test to find out how well your body uses sugar and carbohydrates. It is necessary to follow these instructions for a reliable result of your glucose tolerance test. If you are not able to adhere to these instructions you may find your test cancelled.

Smoking: Do not smoke for 24 hours before or during the test.
Alcohol: Limit your alcohol intake for 3 full days prior to the test to one drink or less per day.
Meals: It is necessary to follow a High Carbohydrate Diet for 3 full days before the test. This diet includes sugar, fruits, bread and cereals as per meal plan. An example meal plan is provided and is intended as a guide only.There is no need to restrict tea, coffee or soft drinks. Continue to use your normal amounts of sugar sweetening.
Example Meal Plan

Breakfast
1 serve sugar sweetened fruit or 1 large glass (200mls) fruit juice.
3 serves bread or Cereal (1 slice bread or 1/2 cup cereal or 1/3 cup cooked rice = 1 serve)
2 teaspoons jam or honey
Eggs, cheese, meat, milk and butter or margarine may be included as desired.

Lunch or Tea
3 slices bread, 1 serve fruit (fresh or 1/2 cup stewed or canned)
Meat, eggs, cheese or fish, butter or margarine may be included as desired.

Dinner
1 slice bread or 1 cup thickened soup
1 cup potato or rice or noodles
1 large serve vegetables
1 serve of fruit, 1/2 cup of ice cream or flavoured yoghurt or sweet custard
Meat, poultry, fish, eggs or cheese may be included as desired.

Additional Intake
As snacks during the day include all of the following-2 extra slices of bread or 4 plain biscuits, 1 large (200ml) glass fruit juice.

Fast: The day before the test, eat the evening meal and then fast for 8 to 12 hours. During the fast, please do not eat or drink anything other than water until the test is completed.
Activity: Minimise activity such as walking or exercise the day before the test.
Booking your test

It is essential for you to make an appointment prior to attending your test. Do this by phoning your nearest collection centre.

Your appointment time and date:............................................. .....

Commence your diet on:............................................... ...............

Fast from:............................................. .....................................

When you get to pathology

You will be given a glass of fluid containing glucose. Then blood samples will be taken at regular intervals as ordered by your doctor.

Plan your day to allow for the test to take approximately 2 1/2 hours in entirety.

As part of the test is to rest quietly, if possible, it would assist us and you if you had someone else care or mind your children during the test procedure itself.

You are then free to leave and return to your normal eating and drinking patterns, however, it is important not to leave the area at the end of the test if you feel unwell so please advise our staff.

Please remember, we are here to help you. For further information please contact one of the collection centres.

Keeping your carbs down will not give you an accurate reading for the GTT result. You should be on a high carb diet for few days. I would contact your path lab to get their version of the preparation diet you should be on for 3 days prior to make sure the test results will be accurate if you are worried.

Belle that sounds exactly like what I had to do.

I would follow it, so you get and accurate reading. After you get your results you can then look at the low carb diet on recommendations from your dr.

I didn't have to do anything different for mine except fast from the night before nor do I know anyone else who's had to so I think it's a little unusual to have a special diet like that.

I didn't have to do anything specific before the test either, except for the fasting, hope your results come back nice and low Leasha. :hug:

To explain a little of why they do the high carb before the test:

They are trying to see how your pancrease responds to being put under stress. When you are pregnant and in the last 15 weeks or so you require anything from 2 - 4 times the normal amounts of insulin to process what you are eating. It is to do with all the other hormones affecting how well the insulin is used. GD occurs when your pancreas can't handle that kind of stress load and is not managing to produce enough insulin to metabolise the glucose effectively. By giving you a carb loaded diet for a few days before and then maxing it out with the GTT drink they can get a rough idea of how well your pancreas is performing under stress. If you go low carb before you may get a false negative result. If you then thought Gee I am okay (but actually you have GD but it just didnt show up in that one test) and go back to normal high carb diet you could be doing harm to your body.
On the other hand If you go high carb and get a result just over the limit like the other poster said or get a false positive the worst case is that you will get to do some finger ***** tests for a couple of weeks initially to make sure. If your sugars are all good over a period of time then you can prolly relax a bit more.
Ideally the best way to diagnose GD would be to give every pregnant women a blood testing machine and get them to test several times a day for 2 - 3 weeks as this is much more accurate as you get to see a pattern of how your body is working under everyday circumstances. Unfortunately it is just not practical..... can you imagine the compliance issues....no one would want to do that voluntarily, hence the gross carb loaded GTT test.