Sandwiches, soup, crisps or even a quick biscuit snack... desktop dining is something most of us have done. Either you're too busy to take a break or want people to think you're too important to step away.
The inevitable keyboard crumbs, audible crunching and often powerful odours are enough to wind up even the most easygoing of colleagues.
There are rarely official rules for what you can or cannot eat whilst sitting at your desk. Should firms get tougher on noisy al desko diners? And should we really be eating at our desks anyway?
Almost a quarter of us eat lunch at our desks, a survey by recruitment firm Glassdoor suggests.
Certain foods are guaranteed to cause irritation.
"Egg sandwiches smell out the office, probably one of the nastiest anti-social foods in the Western hemisphere," says Don Burgess, who works for a brewing company.
Ajay, who works for a financial services firm, believes "no smelly food" should be "the golden rule". Ideally, no one should be allowed to eat hot food at all at work, he says.
Daniel, who works in technology, says his office often "reeks of Chinese food or fish", and he believes all food should be eaten in the separate kitchen area provided.
"This not only enforces people pulling themselves away from their screen for a break but also means you don't need to hear the person next to you chewing their food loudly whilst you are trying to concentrate," he says.
Even snacking on fruit is too much for some people to bear. "If you have to eat, no noisy, crunchy apples," says engineer Lucy.
Surely it would be easier for all of us if firms simply banned eating at our desks altogether?
Absolutely not, says David D'Souza, member director at the CIPD, the professional body for HR and people development. This would be "too draconian or too paternalistic," he says.
Instead, he says firms should do as much as possible to encourage people to eat away from their desks.
Managers should set an example by taking regular breaks and encouraging staff to do likewise, he says. But Mr D'Souza also suggests an informal monitoring system, urging colleagues who we know work through lunch to take a breather.
Instinctively, most of us know that stepping away from work, even if it's just for ten minutes, makes us feel better.
Research has also suggested that it can also make us more effective at our jobs.
Workers who skip lunch are ultimately more stressed and less productive, an issue that could eventually lead to burn out, health journalist Christopher Wanjek found in his book about workplace eating habits.