I find this frustrating and confusing.

My trigger is 87, which means my pre-meal readings have been as low as the upper 70s and some in the upper 90s. Prior to my lunch at 1:00 this afternoon, my BG was 83. I had a 6 oz burger patty (85% lean) with 1 slice of cheese and 1 Tbsp low-sugar catsup. Also had 1 cup 0% Greek yogurt (which alone usually makes my BG go down).

More than 5 hours later I took another reading and it was 104. Dinner was already in the oven so I ate. I just had 4 oz of pork tenderloin with a teaspoon of butter.

Why would it have risen so much after a lunch of pure protein, and then stay up there even after more than 5 hours?