Why do some foods, after eating them: make my heart speed off?

Typically food does not do that but caffeine can and caffeine can be in some foods but more than likely it is in what you drink. However, chocolate does have some caffeine and that may be the food that causes your heart to race. If you are so sensitive like this, you should have your thyroid tested to see if hyperthyroid and at the very least be examined by a doctor.