Why does blood tests need to be fasting?

andyrobo

Member
Messages
23
This may be a completely daft question, but why does my 6 monthly blood tests need to be a fsting test? How would having my breakfast affect the results? No one has ever explained that to me and we just take it for granted, but I am nosey and like to know the scientific bit!

Thanks to anyone who knows!

Andrea
 

ShyGirl

Well-Known Member
Messages
467
I've never been told to fast before a blood test , I have mine done at the hospital now.
Maybe they ask because they want to find out how your body tests before eating?
 

sugarless sue

Master
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10,098
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Rude people! Not being able to do the things I want to do.
The Hba1c test does not require fasting but the Cholesterol and certain other tests do.

Any intake of foods, fats, such as milk, will muck up the results of the Cholesterol test. To get the most valuable, accurate information from your blood test, don't sneak even a mint.

As these tests are often taken together then that is why you have to fast.
 

candyfloss

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160
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Processed foods and refined carbohydrates!
andyrobo said:
This may be a completely daft question, but why does my 6 monthly blood tests need to be a fsting test? How would having my breakfast affect the results? No one has ever explained that to me and we just take it for granted, but I am nosey and like to know the scientific bit!

Thanks to anyone who knows!

Andrea

I think thats a good question Andrea and something I had been wondering too!
I mean, its not as if we all go around starving ourselves, is it, so shouldnt tests reflect the normal state we are in, i.e. with something in our tums?!!
Sometimes I wonder if these things are done simply because "its the way we have always done it" :!:
 

brianb

Well-Known Member
Messages
151
Type of diabetes
Type 2
Treatment type
Insulin
I thought it was so that they cpuld get a base line result that is unaffected by the intake of food. We all know what happens when we eat certain foods, our levels go up depending on what food it was. After a 12 hour fast the effects of most foods should be at there minimum and give the doctors a base line to work to.

But I could be wrong!

Brian
 

badmedisin

Well-Known Member
Messages
247
I think it depends which doctor writes out the form for your bloods. HbA1c doesn't need to be fasted but sometimes they make me do it anyway. Never been told to fast before a lipids test. Sometimes I'm told to fast for the plasma glucose and sometimes not. Doctors are fickle :)
Just make sure they give you a morning appointment if they want you to fast!
 

Robbie34

Member
Messages
18
I recently attended a Diabetes education course at the hospital and we were informed that there is now no need for a fasting test for lipids or HbA1c.