The pursuit of optimal health and fitness can be fascinating and frustrating, primarily because it needs to be approached as an individual endeavor. In other words, while research and conventional wisdom can serve as guides, they should never supplant personal experience.

But that requires time and trial and error.

Take my problem of feeling sleepy after lunch as an example.

Most in the medical community believe that consuming carbohydrates especially simple ones exacerbates that sleepy feeling after lunch. That's one of the reasons why for more than 15 years my standard school-day lunch consists of an egg-white omelet and a fibrous vegetable that's mostly complex carbs, normally 110 calories of Brussels sprouts.

The combination has worked well. Back when the main part of my school lunch was four slices of European-style whole-grain bread, I struggled to keep my eyes open if I sat and graded papers after lunch.

I needed to stand at my podium or I'd doze off, losing five minutes here, two minutes there. After the aforementioned lunch of primarily protein and fibrous carbs, however, that rarely happens. I can sit and grade, which is far more efficient since it eliminates the need to walk from the podium to the desk every time I record a score or check a spelling in the dictionary.

But my best proof that any carbs are the culprit of afternoon sleepiness occurs on Sunday afternoons when I drive from my father's house to mine. That's because after doing my typical four-hour training ride that includes some race-type intensity, my body is depleted of the muscle energy called glycogen that's derived from carbohydrates.

I need to make the meal after an effort like that high in complex carbs or I will feel wiped out the next day.

So I have about 400 calories of baked acorn squash along with a protein supplement for muscle repair almost as soon as I get off the bike. I then shower, pack the car, and begin the drive.

About 90 minutes after my high-carb meal usually 15 minutes into the drive the drowsy feeling almost always hits. In another 15 it sometimes subsides though occasionally it intensifies, and then I'm doing all I can to stay awake and in between the yellow and white lines.

On those drives, I chew wads of sugar-free peppermint or cinnamon gum. (I don't enjoy chewing gum, but the smell of both flavors supposedly makes you more alert.) I roll down the windows in winter, crank up the AC in the summer, and blare the radio on those days when the other tricks don't work.

So why am I sharing my sleepiness with you? Because according to a recent study, I should never feel that way at the wheel.

Never.

Research performed at the Penn State College of Medicine in Hershey and presented in June at SLEEP 2013, the 27th annual meeting of the Associated Professional Sleep Societies LLC, revealed that the amount of fat consumed, not carbohydrates, correlates to increased daytime sleepiness.

How can this be true?

The lunch featuring acorn squash that I described contains no more than 4 grams of fat, or 7 percent of the total calories. Acorn squash contains .9 gram per 400 baked calories, the protein supplement has what the label calls "a trivial amount" and two servings comes to less than 1 gram, but I do use a few pumps of Parkay Spray, a butter substitute that claims no fat per serving but does contain soybean oil.

Additionally, the Penn State research eliminated protein ingestion as a cause for daytime sleepiness. In fact, the research was so definitive that Alexandros Vgontzas, a professor of psychiatry at the Penn State College of Medicine in Hershey and the leader of the study, declared, "Increased fat consumption has an acute adverse effect on alertness of other healthy, non-obese adults."

So why do I fear for my safety when I drive after a hard ride followed by a meal high in complex carbohydrates?

The sleepiness does not result from the exertion of the effort. I know that because I can never recall a time when driving back from an actual bicycle race that I've felt this way even though I'm sure to ingest a couple hundred calories of carbs immediately after a race to begin the recovery process.

And according to the aforementioned research, my sleepiness can't have anything to do with my age, gender, body mass index, or total amount of sleep I get. The results accrued at Penn State were independent of all these factors.

Yet the mystery deepens. The Penn State research found that higher carbohydrate intake increased alertness. So on those drives from my father's house on Sundays I should feel wired not weary.

So how am I and you supposed to make sense of this? Simply by recognizing that studies can't supplant personal experience.