If two different sets of directions get you to the same destination in the same amount of time, which set should you use? Whichever set you understand better. Whichever set makes more sense to you.

If those answers strike you as being ridiculously obvious, ask yourself a related question: "Do I apply the same common sense to my health and fitness?" Specifically, do you recognize the similarities between certain buzzwords or emerging beliefs and use the easier ones to understand the more difficult?That little trick can turn what first reads like college-level kinesiology into junior high school science.Last week, you read about research done in the field of epigenetics without ever receiving the word's dictionary definition: the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself. Instead, I related the idea to personality: how difficult or demanding situations reveal different parts of yours, but that these situations don't really change it; they simply move certain traits of it to the forefront.I did so because my initial attempts to distinguish epigenetics from genetics made my head spin. Consequently, I did what this column suggests you do: Even though I typed "epigenetics," I thought "genetically predisposed."Years before the word "epigenetics" gained widespread use, I used the phrase "genetically predisposed" in this column to explain how the challenge of becoming - or remaining - healthy and fit differed from person to person as a result of inherited genes.In other words, if the lanky, 12-year-old girl who eats everything in sight without gaining an ounce looks around the family reunion and sees nothing but flabby-armed, big-bellied, and huge-hipped 40-year-old females, she is destined to look that way 30 years from now - unless she takes steps to mitigate her genetic disposition. Compared to her built-the-same-way best friend whose mother and aunts still retain girlish shapes, she'll need to be a far more diligent a dieter, a far more energetic exerciser - or eventually she'll look more like her mother and aunts and less like her best friend's relatives.Only when I realized epigenetics is really nothing more than the name for how that 12-year-olds' present and future actions affect the genetic hand she's been dealt, - what I used to call her genetic disposition - did the concept of epigenetics really make sense to me.I share this strategy because last week's column didn't cover all the research related to epigenetics that could help you keep you weight in line without compromising your health, and I want you to understand and benefit from it.The sleep study discussed last week made an important point, but the manner in which it did so may have struck you as far-fetched. It determined that even a one night's disruption created epigenetic changes that make weight gain and type 2 diabetes more likely.But the way the sleep was disrupted was far from typical. The subjects were allowed bed rest, but kept from ever falling asleep. The results of another study released by The Endocrine Society earlier this year suggests that sleep loss that's more typical produces the same effects.In this study sleep loss was limited to 30 minutes a night and only during the days most of us don't get enough - the weekdays. Yet this seemingly subtle sleep deficient still triggered the same metabolic disruptions created by not sleeping for an entire night that encourage weight gain and increase the chance of developing type 2 diabetes.So how are you to rationalize that some people habitually sleep no more than 5 or 6 hours a night, keep their weight at bay, avoid a single symptom of type 2 diabetes - let alone the disease - and even manage to thrive on such a small amount of shut eye? Epigenetics.While epigenetics explains the outliers, the two studies explain what occurs to the majority of people who shortchange sleep. So if you're constantly sleep deprived and start getting more rest, that actually could be more beneficial to your overall health than two more obvious health improvements: increasing exercise time or improving eating habits.The other study discussed last week suggests that if your family has been poorly nourished for generations, your body has learned how to conserve calories to such a degree that "normal" food consumption creates more-than-normal weight gain. Research conducted at the Virginia Tech College of Agriculture and Life Science, however, suggests that you can't always blame your ancestors for adversely affecting your metabolism. You can do it to yourself in as little as five days with a diet featuring fatty foods.The study published in the journal Obesity found that when college students ate their typical number of daily calories but increased the percentage of fat in them to around 55 percent for five days, their muscles received energy differently.Now the point to the study was not if fatty food leads to immediate weight gain. It didn't and shouldn't when the researchers made sure the calories ingested remained the same and the study only lasted five days.And insulin secretion should never increase when simple carbohydrates - the great insulin releaser - get replaced in the diet with any other macronutrient.The point was that the bodies were so quick to react to what most would see as a moderate dietary change.What that could very well mean for you is that there truly is no such thing as a cheat day in terms of health when you're on a diet.