In my opinion, both are acceptable. That is, both are common. Americans often seem to use the fewest words necessary when they speak, so they eliminate "the" in the second example. This might be related to the principle of ''conservatioon of effort" which applies not only to linguistics but also to many other areas of life.

Hey Maria, Cocopop and Dancingbear is correct. They are both correct and acceptable. I would use the second one too. At least it saves me time and saliva from saying "the" . For example if someone asks me "What are you eating?" You could answer any of the 2:- I'm eating an apple I'm eating apple Still I would choose the second option, =)

Hi Maria! They are both correct enough, however if I was speaking, I would use the second option - it sounds more natural.