Who knows where junk food cravings come from? They're like magnets—they just kind of exist, and have powers, and who knows what else there is to them on a scientific level. For some reason, toenail clippers stick to your fridge, and for another reason, you suddenly experience acute pangs of longing for barbecue-flavored processed meat sticks at 3 PM on a Wednesday.
Scientists seem to think there's more to it, after all. In fact, your cravings could have a surprising source: not your proclivity for White Widow bong rips or your earnest belief in the culinary integrity of nacho cheese flavor crystals, but the food experiences from two distinct phases in your life where you're highly susceptible to the allure of the bacon-burger-and-fries lifestyle.
According to researchers at Australia's University of Adelaide, there are two pivotal "moments" (or periods, rather) in your life that determine whether you will embrace the junk food darkness or turn away and become one of those bloggers who only eats ascetic "acai bowls." That's not to say that your diet and lifestyle aren't completely reversible at any time, but surely you've noticed that some of your friends could live off of donut holes while others are perfectly content to munch on undressed kale salads day in and day out.
In a statement, the researchers explain that the two phases are during late pregnancy—when in-utero fetuses experience the most intense effects of their mother's habits—and teenagehood, when you're morphing from an innocent child into an actual Adult Human Being, your good habits or bad habits coming along for the ride.
A 2013 study from the same university first described the observation that expecting mothers who plow their way through all of the pizza bites and jars of Nutella that they can stomach are more likely to have children who prefer high-fat, sugary foods, but follow-up research confirms that fact. Dr. Jessica Gugusheff—a post-doctoral researcher at the School of Agriculture, Food, and Wine—reiterates that even if a woman hits the snack aisle hard early in her pregnancy, the last few months of baby-growing could be an opportunity to reduce the harmful effects on (and future bad eating habits of) her bun in the oven.
The variable at stake is the function of the dopamine response to tasty fatty and sugary foods. Essentially, your brain gives you feel-good feelings when you eat something like ice cream or french fries, but over time, that reaction becomes desensitized. As a result, many people will develop an "addictive" behavior in regards to that reward system, requiring more and more of those types of foods in order to get the same pseudo-highness. This trigger can even result in withdrawals similar to those experienced by drug users.
Gugusheff also points out that in terms of the second zone of dietary vulnerability—adolescence—the swap to a healthier regimen seems to have a profound effect in men, but not women. These two life phases are when the brain is growing at its fastest rate, and is the most vulnerable to being altered.
If you're looking to create some progeny in the next few years, keep in mind that pregnancy cravings—though notoriously strong—are basically transferable. And if you fuck that up, try to get your offspring on some green juice when they hit the eighth grade, and hope for the best.
But if you're an adult and reading this: hey, it's too late now. Your personal longing for nachos, or lack thereof, is fairly well-established. But you may benefit from another recent study that found that a brisk 15-minute walk can mitigate your desire to snack.
Snacks can always attack, but there are (thankfully) ways to fight back.