Why Your Brain Craves Junk Food Later in the Day
As it gets later in the day, your mind starts thinking more highly of unhealthy food.
Find yourself in a constant loop of healthy eating in the morning, followed by an irrepresible urge for junk in the afternoon? You're not alone. According to a new study, the brain gets more positive about unhealthy food later in the day.
Researchers at Australia's Flinders University and Liverpool University recently set out to determine why it is junk food cravings seem to run rampant as the hours tick on. They concocted a psychological experiment that monitored the "implicit associations" certain terms and images brought to mind at different points of the day. The study group included over 300 women, aged 17-25, who had to react to each image with a "positive or negative" vote.
According to the Daily Mail, the words and photos shown to the women throughout the study intermingled the good (holidays, peace, and love) with the bad (death, pain), alongside a variety of food items, like chocolate, pizza, and cake. Starting midday, the participants' reactions to these images were recorded every hour. Their conclusions, which were published in the journal Food Quality and Preference, showed that while the terms and images that weren't food-related—like peace and love—generally gauged a consistent response despite the time of day, the food items did show a shift in perception as the hours went by. Later in the day, more of the study participants were likely react positively to junk foods that they'd viewed negatively earlier.
The conclusion: Just as a person might perceive alcohol as a detriment to their health early in the day and then hit happy hour without a second thought, our resistance to unhealthy snacks wanes as the day goes on. "Individuals who participated later in the day tended to implicitly evaluate unhealthy snack food as more positive than those who had participated earlier in the day," the report states.
Researchers claim the reason for these latent cravings are likely a combination of body and mind: a mix of hunger and psychological perception—and say that outside cultural pressure might also play a part. So, the next time you're digging into a pint of Ben and Jerry's at the end of a long day, know you're not alone in your cravings.