The Science Behind your Cravings


Today’s post is brought to you by our intern Zoe Saliba. She is a high school student currently studying culinary arts.

We all know that junk food is bad for us and we tend to resist the urge to eat it, but what causes some of us to sneak back into the kitchen late at night for just one more bite of that delightfully unhealthy doughnut?



Or two? Or four?

Well, for starters, scientists and food manufactures analyze many factors that can make food more addictive. They create a perfect combination of fat, sugar, and salt that creates excitement and makes you want to come back for more.


Practicing food scientist for more than 20 years, Steven Witherly, author of “Why Humans Like Junk Food” (2007) has created a breakdown of the factors that food scientists tend to use to cause cravings.

Dynamic Contrast relates to the different food textures and tastes found in one product, i.e., crunchy and silky or sweet and savory, that causes us to keep eating these foods. Witherly adds that the dynamic contrast rule “applies to a variety of our favorite food structures—the caramelized top of a crème brûlée, a slice of pizza, or an Oreo cookie—the brain finds crunching through something like this very novel and thrilling.” Therefore, we continue to eat these unhealthy products because our brains are fascinated by this sensation and never get tired of it.

Vanishing Caloric Density refers to foods that vanish quickly and are not very filling, such as buttered popcorn or cotton candy. Since these foods tend to melt in our mouths and are gone quickly, our brains respond with a signal to eat more because they are tricked into thinking that the amount of calories are lower than they truly are. Witherly explains this phenomenon when discussing a Cheeto’s ability to melt in the mouth,“If something melts down quickly, your brain thinks that there’s no calories in it . . . you can just keep eating it forever.” Therefore, we continue to eat these foods because our brains believe we are eating less than we really are.


Salivation Response analyzes how people crave foods that stimulate saliva when they eat. Saliva allows the food to reach the taste buds, and if food cannot contact the taste buds, we do not experience any pleasure while eating. Food scientists use this factor by adding fat to dry foods, such as potato chips which have 50% fat calories, in order to stimulate salivation responses.

Super Size Me discusses how larger portions of calorie-rich foods, such as a “Monster Burger” or supersized fries, are more desirable. This relates to the fact that in our evolutionary past food was hard to find. Therefore, subconsciously our brains want us to get the most out of foods that will give us energy, so we eat more. A study about eating popcorn at the movies, conducted by Brian Wansink, director at the Cornell Food and Brand Lab, showed that people who ordered larger portions ate 34% more than those who ordered smaller portions. Clearly, if we are given larger portions, we will eat more.

Mere Exposure Effect discusses how repeated exposure to foods that stimulate a happy sensation or memory will increase the chance of craving those foods. Regarding junk food, manufacturers and marketing agents use ads to expose customers to their products causing them to remember a time when they ate a similar product and felt happy. This then allows their product to stay in the customer’s mind long after being exposed to the ad.

Food science is an emerging field and scientists will continue to expertly tweak major companies’ products in order to verify that these products will be well-liked and will cause the customers to always come back for more. Junk food cravings are hard to avoid because of the psychological properties that accompany them. We have to understand that simply avoiding eating junk food is easier said then done. However, through determination and perseverance, one can steer away from junk foods and towards healthier options.



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4 Responses to The Science Behind your Cravings

  1. Sanika says:

    This article was so insightful and the facts were very helpful as well! Great job Zoe!

  2. Sydney says:

    As a High School student myself, I found this article extremely interesting and would love to read additional articles from this author. In this day and age it is difficult to understand what is and what is not healthy. Now, from reading this article, I can identify how unhealthy food manufacturers get us “hooked” and how there truly are secrets and an exact science within the food industry. Thanks for the fabulous article! I would love to hear more!

    • U Rock Girls says:

      Sydney, thanks for the positive feedback. Stay tuned for more great articles. Let us know what you would like to see from us!

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