Some lunches are being forfeited by employees, but companies also have come under fire for not granting their workers enough of a break.

In 2005, a California jury awarded more than $172 million to more than 100,000 current and former Wal-Mart workers who claimed they were illegally denied lunch breaks and asked to clock back in before their breaks were over.

Executives, professionals and other non-hourly employees are generally not entitled under federal law to any break for lunch, according to Robin Bond, an employment lawyer in Wayne, Pa.

But employees who are paid hourly or who are covered under union collective bargaining agreements typically are supposed to get regular breaks, including a 30-minute lunch for five hours of work.

Employers could face legal claims from eligible hourly workers who aren't given those breaks, or even from eligible employees who voluntarily work through lunch.

Some states, such as California, also have their own statutes mandating lunch breaks for workers.

"I see more and more in our culture where being overworked is a badge of courage. It's a major mistake to let work encroach even further on this time," Bond says.

"People really need a break."