One time I accidentally ate a snack before a blood test. They called me and asked if I ate and I remembered I did. They said my sugar was spiked, but can tell through that it’s not normally like that because of some three month marker. I may be repeating that completely wrong, but how is it possible to see that your sugar isn’t normally high and just acutely through blood? I only get annual physicals, so it’s not like I had a blood test 3 months prior.