I never eat lunch at my desk because I think it's inconsiderate to my coworkers. They should not have to smell or see what I am eating, let alone hear me crunch into chips or an apple.
I find this quite ridiculous, people are not these fragile creatures that can't see, hear or smell anything other than the usual office sights, sounds and aromas. I think you're over thinking this. Unless you're eating weird stuff like boiled lungfish or whatever then I suspect nobody is paying the slightest attention to you eating chips or an apple.
In a loud office, it might not be so bad, but when the office is otherwise quiet, it keeps you from concentrating at all. CRUNCH. CRUNCH. cr-cr-cr-cr-CRUNCHCHCHCHCH.