Well it doesn't have to come in the form of energy loss in the day... too much sugar (look at all the foods you eat - probably getting at least 50g of sugar without even trying), and it can lead to interrupting the sleep cycle.
But your body may also be designed with short but multiple sleep periods. It's actually a rather natural and native habit, but it's fell out of practice thanks to the schedule of the industrial work force, which translated to the same type of shifts in the white-collar world.
When you're in the office-world, it's not nearly engaging enough - in the physical sense - to have the energy as when working manual labor for a single shift. And truth be told, the developed civilization basically adapted to the shift and labor world. Not too much wrong if your body instinctively adapts to this shift world and operates at peak with a single block of sleep, but for the rest of the species that don't adapt, they are most productive when they get two or three sleep cycles in the day. As long as the blocks of time sync up with the natural and complete REM cycle, you'd actually be your most productive possible during all waking hours. Problem is, such a sleep schedule can be hard to use it effectively in the 8-5 world.
Though it is possible.
I can't remember the exact suggestions I had read elsewhere, but it's something like a moderate-length block of sleep before work (something like 12-6 for most people, though 1-6 and and 12-6:30 depending on the individual), and then a 20 minute nap during your lunch break, and after work either another 20 minute nap, or an hour and a half of sleep, and you're good to around midnight again.
It might not be as effective as multiple similar-length blocks of sleep, like 90 minutes thrice, followed up with a 180 minute phase. Problem there, you get a few interesting waking hours, two that are during the typical sleep time of most individuals.