About eliasoziolor

My name is Elias and I am a senior at DePauw University double majoring in Biology and Biochemistry. I was born and raised in the small town of Razgrad in Bulgaria, though I pursued my high school education in the capital, Sofia. I have been interested in science since I was a kid. Being a part of the math club in middle school and picking physics electives in high school I tried to always progress in various scientific fields. At DePauw I became part of the Science Research Fellows program as a lateral entry, which gave me the opportunity to pursue various projects including amphibian immunology, aquatic ecology and molecular biology. My latest project was at a joint program between Harvard Medical School and Massachusetts General Hospital where I studied inflammatory signaling in human intestinal epithelial cells. DePauw also has given me the opportunity to pursue a wide variety of extracurricular activities including being a First-Year Residence Assistant, Prindle Ethics Intern, DJ at the local radio and an Immunolgy tutor. All my experiences made me interested at how science explains the world around and I hope to make you as curious and excited about science through my posts in this blog.

Food Cravings and what those foods do to your brain!

Ever find yourself staring at that delicious chocolate cake or pumpkin pie on the shelf and with your mouth watering just at the sight of it? Then you know how craving food feels like.

Scientists define food craving as the intense desire for a very specific food and your willingness to go out of your way to receive it. A lot of us blame ourselves for giving into those cravings “letting go” by indulging into something either sweet or very fatty, but there are many scientific facts that now allow us to understand why those foods are so tempting.

Many questions may arise when you think about food craving and I will attempt to answer a couple with this post, starting with: What types of foods do we crave and why?

Many of us think of craving as the desire for something sweet, but scientists at Tufts University did a wide study, where they found that even though sugary foods are preferred, fats are not left behind. The craving for a specific type of food differs on a personal basis, but we mainly tend to go for foods that are very calorie dense and tend to go for a combination of carbohydrate and fat rich food. An interesting thing that those researchers also found is that the craving intensity did not depend on body mass index of the people tested. Lean people experienced just as much craving as obese ones, but the obese ones would need bigger amount of food to satiate that craving.

So why do we have those cravings is the next most logical question? The only theory that holds strong logic in this case is derived from our evolutionary history. Any species needs nutrition to survive and through the years nutrition has not been as readily available as it is now. Thus, it would be more beneficial for our predecessors to find food that is highly packed with those vital calories they would need. So in the idea of “survival of the fittest”, the fit specimen would be the ones able to find enough calories to survive, thus the ones that seek them most avidly are the ones that find them. On the other hand, that doesn’t mean that you can blame your ancestors for all your cravings, it’s partly your fault!

Now that we know that we can partly blame evolution this leads us to two more questions: What exactly happens that causes us to crave and why are we in part to blame for cravings?

Researchers at Johns Hopkins Medical School have found that there are specific centers that light up in the brain on a functional MRI (magnetic resonance imaging) when people think about foods they crave. The fact that those sections light up, shows they are activated. The more interesting thing is that those sections don’t activate when we think about low calorie food, but also that those are the same parts of the brain connected to drug addiction.

The amygdale, hypocampus and nucleus accumbens are strongly associated centers of pleasure. Those are the same places that drugs activate and those are the same places activated by the sight or thought of craved foods. Through those images the researchers also found something even more fascinating: when lean people consume craved food those sections light up more strongly than in obese people. Lesson learned – leaner people experience more satisfaction from the food than obese people, who have to consume more to receive the same satisfaction.

So why should we in part blame ourselves for our cravings? The more often you indulge on these “craved” foods you train your brain to get accustomed to them, a process called “sensitization.” The more accustomed your brain is, the less satisfaction you receive from eating that food you craved. The less satisfaction you get the bigger amount you crave. It is a vicious cycle that leads into obesity and depression very fast. Food addiction is real and it is not to be undermined.

To leave you on a positive note all of this is to just remind you that “craving” food is absolutely normal and 96% of people experience it. The difference is that if you indulge on that craving frequently it will become stronger. The good side is that like any addiction it can be overcome. As long as you stick to a good diet, it is estimated that you can go back to the same amount of craving as a “lean” person within 3-6 months. Hope that helps!

Sources:

Beaver, J., et. al. “Individual Differences in Reward Drive Predict Neural Responses to Images of Food.” Journal of Neuroscience. Vol. 26(19) Pg:5160 –5166. May 10, 2006

Pelchat, M. et. al. “Images of desire: food-craving activation during fMRI.” NeuroImage. Vol. 23. Pg 1486-1493. 2004

Bryant, R., Dundes, L. “Fast food perceptions: A pilot study of college students in Spain and the United States.” Apetite. Vol 51. Pg. 327-330. 2008

Gilhooly C., et. al. “Food cravings and energy regulation: the characteristics of craved foods and their relationship with eating behaviors and weight change during 6 months of dietary energy restriction.” International Journal of Obesity. Vol 12. Pg 1849-58. 2007

Tufts University, Health Sciences. “Links Between Food Cravings, Types Of Cravings, And Weight Management.” ScienceDaily, 18 Jul. 2007. Web. 24 Nov. 2011


Advertisements