That is not a lot of information to go off of and could be almost anything. It is likely related to the increased metabolic demand for digestion. If it causes symptoms or if you are worried about it, you should probably talk to your doctor.
Do you sometimes get light headed after a heart palpataton?
Same thing happens to me when I drink cold water. My heart can be crusising along at 65 bpm, and when I drink cold water it jumps up in the high 80's. I would guess that's harmless if your heart is otherwise healthy.
Give it a try, it may be your iced drink, not your food.
This happens to me every time I eat, and epecially if it is a large meal. I would assume that there is nothing wrong, but you may want to get it checked out