Experiments of Obesity in Rats

http://www.sciencenewsforkids.org/articles/20091028/Note3.asp


   This article describes an experiment that scientist Paul Johnson, of the Scripps Research Institute, ran on rats.  He and fellow colleagues tested two groups of rats.  To one group they fed human junk food regularly, and to the other they gave regular dietary food for rats.
    The group being fed junk food daily exhibited abnormal reactions.  As they ate each day, they ate more and more food.  This prooved to be the same type of habit that forms in rats that are being given heroin, a known dangerous drug.  The rats become addicted, and crave more calories and fat each day.  Scientists find that this is because the junk food stimulates the release of pleasurable hormones, that come out whenever the rats digest the fatty foods.
    The brain starts to go numb to the foods after a while, and then requires more food for it to keep releasing the hormones.  They monitor the rats brains, the "pleasure center", to see what is exactly happening.  Overall, as the data of the addiction to junk food is compared to drug addiction, it is found to be quite similar in many ways.  This helps scientists immensely, for it gives them a deeper understanding of how it is prooved quite possible to somehow stop obesity in humans.