The short answer is no, but (there is always a but, isn’t there?) you could get a secondary offense ticket as a result. That got your attention, didn’t it?
Yes. The simple act of eating while driving is not illegal per se and won’t get you a ticket, but your actions as a result of eating and driving can. A police officer can pull you over if you are driving carelessly (which may be because you are eating while driving), and can give you a ticket for the distracted driving.
But, in Washington state, it is possible for you to get a distracted driving citation and then on top of that an additional citation, if the officer sees that you were eating while driving. In fact, Washington has become way more stricter on their driving laws and eating while on the road could lead to a ticket starting at $99 (and can just keep on going up if you are found to be partaking in other destructive behaviors such as grooming while driving).
So be careful, if you plan to eat while driving in Washington. (Of course, that doesn’t mean you
should be less careful in other states, but fair warning).