Remind me why we fast for blood tests?

[JCMartin]

My friends getting tested and says you dont need to fast - can you remind me why its a good idea please?

[tattybogle]

read the 4th reply to this post:

healthunlocked.com/thyroidu....

starting :

" THE NHS SAY THE TSH TEST DOES NOT NEED TO BE A FASING TEST ...THIS SHOWS WHY IT SHOULD BE:

A recent paper showing that..... "

[SlowDragon Administrator]

Research suggests food or tea or coffee may affect TSH

even if breakfast, tea or coffee don’t affect results…..

Last dose levothyroxine should be 24 hours before test

And then you will want/need to take levothyroxine immediately after blood test and that needs to be on an empty stomach