It's somewhat uncommon but strange. I will go ahead and say that aside from being overweight with a heart murmur since childhood, I don't really have any other medical problems I am aware of.
Sometimes after a meal, about 15 minutes later my face will suddenly feel red-hot, fatigue creeps up on me so much that I just want to curl up and take a nap, and I can feel my pulse pounding in my head and chest like my heart is pounding hard, but not fast. I'm not sure if this is some mild food allergy, as I am feeling the effects right now after a simple meal and was finally driven enough to search for answers.
My meal consisted of:
Sliced smoked turkey breast, made into a sandwich with a little mayo, mustard, American cheese slice
Two dill pickle spears
Roughly 15 snack-size pretzels
It wasn't much, but definitely enough to satisfy me for several hours. I'm just kinda at a loss as to why I sometimes feel like this. Still, I have no known food allergies. The only medications I am on are Zoloft (Setraline) and a birth control implant (Implanon/Nexplanon, can't remember which) in my arm.