Here's a conspiracy theory about McDonald's (MCD 0.38%) that may turn out to be true: I believe the fast food giant is secretly working on plans to begin serving breakfast all day.

This isn't just a random guess. In fact, I'm not even the first person to bring it up over the past few weeks. At the end of February, the Associated Press published a piece titled "McDonald's eyes longer breakfast hours."

The article was based on a handful of cryptic quotes from the head of McDonald's domestic operations, Jeff Stratton. "We know, as an example, that breakfast on the weekend cut off at 10:30 doesn't go very well," Stratton said in an interview.

But when asked to provide details, he deferred. "Well, we're just beginning," he said. "We're just taking a look at it."

So, here's the question: Is McDonald's just "taking a look," as Stratton seems to suggest, or could there be something more to this?

I believe it's the latter. And I say so for one reason.

In the past, logistics have been the most commonly cited issue holding McDonald's back from extending its breakfast hours. Specifically, its kitchens are designed in such a way that breakfast and lunch items can't be prepared simultaneously.

This may seem odd, but it's important to remember that everything McDonald's does, from how its restaurants are laid out to the structure of its supply chain, is organized to maximize efficiency. As a result, if frying hash browns interferes with preparing French fries, then something's gotta give.

But -- and here's where this transforms from a conspiracy theory into a reasonable suspicion -- McDonald's is pouring millions of dollars into removing the logistical roadblock.

At a McDonald's investor day four months ago, a number of executives discussed the chain's decision to scale back its reimagining of restaurants in favor of "prioritizing some investments in our kitchens to deliver enhanced service capabilities and menu choices to our customers."

Among other things, these investments include new assembly tables that will be installed in the kitchens of all restaurants by 2014, the purpose of which is to offer "greater customization by accommodating more ingredients" and to "improve overall speed of service."

This is all very fine and well, of course, but it also presents McDonald's with the opportunity to make the structural changes necessary to accommodate dual meal services.

And why would it not?

If it's true that McDonald's has "long entertained the idea of serving breakfast throughout the day," as the Associated Press reported, then this would be the perfect opportunity to make that possible.

All of this remains conjecture, of course. But with Taco Bell entering the national breakfast scene and rumors that quick-service chains such as Chipotle Mexican Grill could soon do so as well, neither customers nor investors should be surprised if McDonald's moves to defend its morning fast-food fiefdom by all means necessary -- even if that entails serving sausage biscuits at noon in the place of Big Macs.