“Bet You Can’t Eat Just One!”
Ever had that moment where you simply had to eat another one of those pre-packaged cookies or slice of suspiciously colorful sheet cake even though you weren’t really hungry or, in all honesty, it didn’t taste that amazing. Guess what! It’s not all in your mind!
Well, it is….but that’s the point.
Addiction to “junk food” isn’t just a lame excuse, it’s a very real thing. Today’s processed junk foods are scientifically designed to be highly palatable and trigger the mesolimbic dopaminergic system, or “reward section,” of our brain. They literally affect the same reward circuits activated in drug addiction.
In a healthy functioning system, appetite regulation moderates energy intake and deficits, causing you to feel hungry when you actually need food, and full when you do not. But junk food disrupts this system. Although typically high in calories (meaning they should shut off appetite in theory), junk food actually increases hunger while simultaneously decreasing satiety signals. As one study notes, “Activation of the mesolimbic reward pathway creates a sense of pleasure and interferes with physiological satiety signals, which promotes the further consumption of palatable foods.”
And the addiction to these foods is strong, tying into our hedonistic pathways. Like an addictive drug such as cocaine or heroin, junk food provides a hit of pleasure, while raising the threshold for that pleasure. More and more of the substance is then required to achieve the same effect. In clinical studies, rats fed diets of junk food would voluntarily undergo painful shocks in order to receive more of the junk food. Those poor rats. (Who represent us, just saying.)
In fact, junk food’s alterations to the brain’s neural network for appetite regulation can begin in the womb. One study found that when pregnant rats were fed junk food, it altered the mesolimbic reward pathway of the offspring. The baby rats were more inclined to seek out highly palatable junk food and become obese. This is especially troublesome, given that, as of 2013, more than 50% of women are overweight or obese when pregnant. In other words, a majority of children born today may be “programmed” from the beginning to crave junk food.
Even though I’ve successfully eradicated most cravings since going Paleo and implementing intermittent fasting, the Funfetti cake still calls to me every time I pass it in the store. Curse you, Pillsbury Doughboy!