it would also reveal correlations between blood sugar levels and symptoms too
sometimes the food-effect correlations can be hard to notice, i discovered that back in 2014 when i got a really bad chronic allergic asthma problem come up after 7 months on jail food
like, for one thing, i found that caffeine suppressed the allergy symptoms, but it had such a weak effect after a few days trying to keep that going i developed severe sleep problems
i also found numerous foods triggered it, brown rice, whole grain wheat was worse than white, cucumber, tomato, capsicum, to a lesser extent also milk and yoghurt
it helped in other ways but the milk diet resulted in a lot of weight gain also... low GI but high energy...
it's horrible, like being imprisoned in a room with a psychopath who is invisible and you can never know or see where he is gonna attack you from next