Years ago, I was working at a company on the west coast, a CDN that was a competitor to Akamai, that eventually got swallowed by Akamai's far larger delivery network. 

What I remember most is dinnertime. Yes dinnertime. We had these buffet dinners meant to encourage employees to stay a little later, work a little longer. At least to burn a little primetime oil.

Interestingly, in the same vein, years later, I noticed on a visit to the Google Headquarters that people were privileged to a similar kind of idea, namely, eat at the company, the spread a lot larger at Google than at any prior company I worked at of course.

The real question is does a satisfied stomach produce better employee morale.

Interestingly, this study at Spherion says it does, indicating that: "30 percent of workers reported that the availability of food throughout the day contributes to their workplace happiness."

Here's the study if you'd like to read it in its entirety: Study on Employee Happiness

Funny though, I do come in contact with so many people that say if only I got a raise, I'd be a bit happier. I guess those people didn't make it into this study.

Regardless, it sounds like hiring a full time chef might not be a bad idea if your company can afford to. Even for a small company: I spoke to a colleague at pricecheckpro.com who has a fully stocked kitchen for employees to snack on. He said that more often than not, "employees want a quick fix" and that "having food on hand saves time and trips out of the office". His company isn't trying to get the employees to stay later, but to work productively during the time they are there. I think that is the right way to do it! Zero guilt involved. Though I'll admit, I like a stroll from my desk every now and then.