You walk into brain break and survey your options. If you’re faced with the choice between an apple and a brownie, chances are your instincts will guide you towards the brownie; try as we might, we just can’t stop reaching for fat and sugar.

Human evolutionary biology professor Daniel E. Lieberman '86 is an expert on the evolutionary logic behind these patterns. In his newest book, "The Story of the Human Body: Evolution, Health and Disease," Lieberman tells us about the evolutionary causes and effects of “mismatch diseases,” which occur as a result of long-term changes in our environment but not our bodies.

We spoke with Lieberman about his book and what it might mean for college students in their day-to-day lives.

According to Lieberman, human beings evolved to become “adapted to eating a diet high in fiber and low in sugar, but craving fat, sugar, and salt.” This diet was suitable to our active lives at a time when our primary activities were making and using tools, hunting, and gathering, Lieberman said.

Now, take a caveman out of his cave and drop him into a college dorm. What happens?

We’ll give you the bad news first. Our environment today is so significantly different from that of the caveman’s that the caveman would be likely, if he followed his dietary instincts, to suffer from mismatch diseases such as heart disease.

Although we, the caveman’s ancestors, live relatively inactive lives, most of us choose to consume a diet high in sugar and fat. This choice is problematic because it is not balanced out with hunting and gathering activities, Lieberman said.

So what’s the solution to this problem? Since we can’t change our genes, Lieberman told Flyby, we must change our environment.

The good news is, we can do this in three key ways—all of which, thanks to our instincts, are far easier said than done.

First, Lieberman suggested, choose a more healthy diet involving less simple sugar and carbohydrates, which we are adapted to be unable to digest quickly in large amounts. (Real question: does HUDS know this? Because they’re not making it any easier for us).

Second, get physical exercise. (Walking to the Quad doesn’t count).

Third, sleep enough; inadequate sleep creates stress in our bodies. (Unfortunately, having to study for three midterms also creates stress in our bodies and usually means less sleep).

Flyby apologizes if these problems and seemingly unattainable solutions have you feeling even more stressed. Maybe now would be a good time to eat your feelings at brain break.