The need for a nap after food is heavily correlated with the quantity and quality of food you're going to eat. Eat light and you won't feel the need for a nap, otherwise it's hard to avoid.
If you treat your digestive system like a dustbin, of course you'll need higher amounts of insulin excretion (also called spike) to digest, higher blood pressure (heavier heart work-load) and all these nice staff which lead to hyper/hypotension disorders and finally to strokes.
That said, I'm sure that if you wake up at 5-6 a.m. a nap around 13:00-14:00 will work for you, but the most important - imho, not sure what studies says, just personal experience - is getting a good night sleep, not a nap the day after.
There's nothing like a good night sleep and there are many factors that determine the night sleep. To mention just a few:
* Food: eating a light healthy meal at least two hours before going to bed is the optimal situation.
* Room temperature: Must be optimal for blanket usage
* Oxygen: Oxygenated room possibly, open the windows a little before going to sleep. Oh and no vegetables sucking oxygen inside the room is better.
* Sound: Trying to keep the bedroom as quiet as possible from external rumors, except maybe if you are living in nature. Natural rumors (birds, grasshoppers, etc) are likely to increase the quality of your sleep but surely nothing digital will. Even if some people believe that TV helps them getting a sleep, they rarely get a quality sleep.
* Relax: A book is at least 10 times better suited than a movie before going to sleep. Relaxes the mind while a movie is like a sort of bombardment, keeping adrenaline flow, when it shouldn't.
And many others :-)