A recent study published in the journal Frontiers in Psychology gives us further evidence why junk food is something we should actively avoid.
Food addiction and junk food aren’t a thing to be trifled with. I’ve said how food addiction is a serious issue that needs more attention. Moreover, a recent study done on rats gives further weight to this notion. While some like to argue that junk food is not all that too bad with the recent findings about how saturated fat and cholesterol are not your primary enemy, there’s still a fiery debate going on about why junk food should be avoided.
It has been mentioned before that eating highly preferable and tasty food, which encompasses junk food as well, leads to different changes in your brain which underlie behavior associated with motivation. The changes go in the direction of lower self-control and increased preference for the same foods. What hasn’t been tested, however, is whether it impacts our perception of these foods as well.
This is what was being tested in the present study.
As I’ve mentioned before, rats are a beloved animal for scientific research and with that said, in a recent study, that is something that was being tested.
In a series of different experiments they basically taught these rats to associate a particular sound cue with a particular flavor of sugar water – cherry and grape. They used Kool Aid, which I’m sure many of you are familiar with.
At the start of the study, the rats, which were fed with a normal rat diet since their birth, responded with a very natural pattern of behavior; after they were being exposed to these sound cues for a while they stopped responding to them. Usually, when scientists condition rats or other subjects like these, they expect that the subjects would respond to the stimulus to which they were being primed to.
For example: Stimulus x (the sound cue) would illicit behavior y (drinking either cherry or grape Kool Aid).
The rats stopped responding to the sound cue because this is a mechanism that’s widespread in animals. It protects them against overeating and promotes a diet which has more variety.
And this is where the junk food part comes in. After the first phase of the study, the same rats were able to eat different cafeteria foods such as cookies, pie, and cake, among others. After two weeks, not only did they gain around 10% weight, they also had some interesting changes in their brains. The natural response to the sound cue “stopped working”. This in effect caused that they didn’t care about the sound cue anymore – the natural mechanism which ensures they don’t overeat was basically diminished. The reward circuitry in their brain was physically altered. Because of this they didn’t care about the fact that they were constantly being exposed to the same junk food.
These results are shocking because they are the equivalent of you wanting to eat more ice cream when you hear the ice cream truck coming, despite eating ice cream moments ago, as one researcher concluded.