It's weird but eating large meals causes my heart to speed up.

Any idea?

Digesting a large meal (or any for that matter) requires increased oxygen to the digestive system. That reduces the amount available to other systems and increases overall heart rate. That is why people make jest of the prototypical MI's following eating Christmas dinner with alcohol and then shovelling snow...Too many demands on the cardiac system....
In other words, nothing to worry about unless you are dumb and overtax the rest of the body at the same time...:)
jan

i have also read that it CAN indicate mild intolerance to that food