Q I work in public service and have been at my job for over a decade. In my office there are 10 of us; each of us carries a caseload of approximately 100 clients, and we are paired up to provide coverage when one of us is sick or on vacation. The nature of our work means that coverage is always needed, since unpredictable, urgent situations often come up.

The colleague I am paired with for coverage is often ill with headaches, stomach issues, dizziness, etc. When she is working she is often forgetful and sometimes rude.

This colleague talks very often about how she fasts each day, not consuming anything except black coffee until 5 p.m., saying it’s the best way to lose weight. I don’t want to lose weight and don’t think that weight or weight loss should be discussed in a professional setting. So I don’t feel I can say, “Hey, maybe if you ate food regularly, you wouldn’t get so many headaches.”

Is there something that I can say to my colleague or my manager that might help this situation?

— Anonymous

A You’re right. You can’t tell your colleague that if she eats more regularly, she won’t get as many headaches. Nor should you bring up weight or weight loss — at all. (I’ve been guilty of this many times in a work environment — though the comments about weight were comments about my struggles with my own.)

But you do have options.

Option 1: Go to your manager and have a frank discussion about these issues. I’m not sure you should mention your theory that your co-worker’s mood or comportment is being influenced by her food intake (or lack thereof), but you do need to resurface the issue, tell her that it is ongoing and explain how it is affecting your work. You also need to ask her to intervene directly. Oh, and be specific, not just about how these personality issues are affecting your work but what form they take and the specific complaints that clients have lodged.

Option 2: Approach your colleague directly. Don’t bring up anything about food — or weight! — but tell her that you have been getting some feedback from your clients that her demeanor has been impolite. Tell her that although you understand your work is challenging in the best of circumstances, the negative feedback continues and that you’d like to discuss some solutions.

Speaking with her may feel a lot more loaded than going to your manager. It is. You have no idea how she will respond, and if she’s as grouchy as you say she is, you have every reason to worry that she might not welcome the conversation. But it’s still important that you have it. I think it will communicate that she needs to be accountable for her behavior, and expressing that your job is being made more difficult may soften the inherent criticism behind your comments and concerns.

Anna Holmes is an award-winning writer, editor and creative exec whose work has appeared in numerous publications, including the New York Times, Washington Post, and The New Yorker.