Hypothetical situation: you are a rat. There is a bowl of cake frosting in front of you. Do you eat it? The answer is yes. You eat it all.

So you’ve eaten an entire bowl of cake frosting—why would you do such a thing? You weren’t that hungry. Now we’re at an impasse. The frosting is gone. It’s behind (or within) you now. Are you satisfied? Was it worth it? You have no answer for what you did, of course. You’re a rat.

Professionals are trying to find answers to this question. While you were eating cake frosting, highly paid researchers were analyzing your tiny rat brain in an effort to figure out what made that cake frosting so darn appetizing. Like many things, it turns out it’s mostly in your head.

Professor Allen Levine is the Dean of the College of Food, Agricultural and Natural Resources Sciences at the U of M. He’s spent more than 20 years researching neural regulation of food intake and he knows more than a little about the science of eating. He held a seminar recently titled “Why Can’t We Stop Eating?” over on the St. Paul campus, Minneapolis’ agrarian little brother. So why can’t we stop eating?

Levine says that there’s not one answer; hunger, taste, and compulsivity, among other things, each have their parts to play. The brain’s perception of these things produces a cocktail of natural chemicals that influence eating habits. Levine notes that this is the reason America’s obesity problem hasn’t been “solved,” despite massive research on the subject: there is no cure-all for being hungry, being stressed, and acting compulsively. People, unfortunately, will be people.

To get a sense of the desire to eat, let’s first address the idea of taste. Things taste good not because they’re healthy for you, but because your brain thinks they’re a source of vital nutrients. Your brain doesn’t want to be “in good health” in the future, it wants to be full and happy now. You eat a jelly doughnut and your brain thinks “om nom nom delicious fats!” because it wasn’t so long ago that humanity subsisted on bread, rice, and the occasional famine. To your brain, fats in any form are welcome. On the flipside, when you try to choke down a few brussel sprouts, your brain thinks “what the heck is this ridiculousness?” You may know that brussel sprouts are healthy, but to your brain, brussel sprouts are gross.

This ties in with the concept of hunger, a straightforward idea if there ever was one. You, no longer a rat for the purpose of this example, eat when you’re hungry. You might eat when you’re not hungry too, but you definitely eat when you’re hungry. You’ll eat brussels sprouts, or jelly doughnuts, or human flesh if the circumstances are particularly dire. Your stomach says “feed me!” and your brain says “feed it!” so you obey or you die. That’s the reality of hunger.

Hunger isn’t the reason people eat too much, though. For that, we have to get into some brain chemistry. Imagine you just had a big meal with your best friends, Perkins style. Texas Roadhouse style. International House of Pancakes style. Now you’re completely full and somebody (probably somebody very strange, all things considered) offers you a big bowl of unflavored oatmeal to top off the meal. Do you eat the oatmeal? Unlikely. You’re full. But what if, instead of unflavored oatmeal, this decidedly strange person offered you a slice of your favorite chocolate Bundt cake? Do you eat that? Quite possibly. So what’s the difference between unflavored oatmeal and chocolate Bundt cake at the end of a meal, besides the obvious?

The Bundt cake triggers the release of endorphins in your brain while the oatmeal does not. Endorphins, also known as opioids, are basically feel-good chemicals. Endorphins are your brain’s way of saying “damn, that was delicious, I’d best have some more,” so even though you know you’re full, you still gain endorphin-derived pleasure by eating the Bundt cake. Temporary happiness via endorphins often wins over future discomfort at having had too much Bundt cake.

Simply put, your brain knows what it likes, whether that be Bundt cake, potato chips, or chocolate ice cream. It doesn’t always know what it needs. Your brain just wants to be happy, and that means it wants endorphins easily acquired from today’s readily available foods.

That’s where you stand, you and your brain and your stomach together. This meager text you just read through is only a short primer on the daily activity of eating. The Wake is not the ideal medium for explanations about the neurochemistry involved in human food consumption. If you, the rat or the meal-taker or the person with a brain, want more information about the craziness that is human desire for food, you’d best do the research and put in the time. Or enroll in CFANS.