I agree the comments above. The only suggestion i haven't seen yet, and which seems like a stealthier option, would be to take in a homemade soup in a flask which you can sip from a cup at your desk. The base of the soup can be bone broth with added butter for taste and satiation. You can make a big batch to last you the whole week. Plus it can be as light (less meat and vegetables) or as heavy (more) as you want it to be.
Oh, and, just incase you fancy a change one day, avocado based smoothies with some berries added for taste could be an option. There's also
fat bombs. And these ideas have the added benefit of looking like 'regular' snacks.
It's likely that eating a bigger breakfast with more protein and fat will stave off hunger, but, depending what your job is, your working hours, sometimes our bodies just need to eat.
If you're having problems with work colleagues, you can always just tell them you're gluten intolerant, or, if you think they'll mock that, then tell them you're Celiac (extremely sensitive to gluten, recognised by the medical profession). Although I agree with aimarok, i'm not sure it's any of their business what you choose to snack on! But then i know office politics means that sometimes it's easier to tell a small lie.
Sadly, if you want to eat well, you have to invest some time. You can find decent things to snack on in super markets, but it's unlikely you'll find anything in the vending machine at work.