OK. Here's the deal: I dislike eating in a cafeteria-like environment. At work, I tend to eat at my desk. I don't particularly like eating my lunch with a bunch of other people, particularly when they're people that I'm only around because we happen to work in the same office. Call it social anxiety, call it reminiscent of being brought to tears in cafeterias throughout my school career, whatever - I just don't.
So, dearest coworker with the best of intentions, get off my freakin' back about eating in the lunch room. Don't tell me it's "not healthy, it's just not good" because I don't want to eat with everyone else. You're at the front desk - it's your bloody JOB to know everyone here. I deal with pieces of paper. That's MY job. So back the hell off.