what in food can cause quickened heart pace? allergies?

i've found sometimes when i break my anti candida (anti sugar) diet my heart rate will speed up. i cant figure out if its allergies (i know leaky gut can cause random food allergies while its healing), an overabundance of Sugar when my bodys not used to having it |(generally if i mess up my diet it almost becomes a binge so i'll take in a lot of sugar) or perhaps an over abunance of fat during that meal?
yesterday i ate a bagle using a loot of coconut oil as the butter |(perhaps it was the coconut oil) which kinda makes me think it may be my body not used to breaking that much fat down...and the fact that i ate...almost a pint of icecream...so Sugar intolerance when you havent had any in a while maybe....gaaaaah
or perhaps it happens when you overstuff yourself because you're bodys workign hard to digest everything?
well, anyways, it scared me last night (i slept it off) so im definitely not stuffing myself/eating bad again|!
thanks for the thoughts/opinions. i'd love to know what can cause it...