My view is this: Always fast for blood tests.
My logic is this:
For most tests, most of the time, fasting might make no difference. Sometimes fasting might make a modest difference. But there are some tests which must be done fasting.
Say we don’t usually fast. Then we are scheduled to have a test which definitely requires fasting.
If that is the only test we are having, fine.
If we have that test in combination with other tests, ones which do not need fasting, this time they are done in a fasting state. Though previously the same tests might have been done without fasting.
Any effects due to fasting (or not), even if small, make comparison with previous tests just a bit more questionable. Was that a real and potentially important difference? Or was it due solely to fasting?
Always fast and the question disappears.
