Your Brain with Junk Food
Clearly, we eat not just to fill our stomachs, but to satisfy a whole range of biochemical impulses. The brain is built to encourage our efforts, not only with the relief of hunger pangs, but also with an intricate hormonal “reward” system.
When it comes to diet, I always say that what nourishes the body nourishes the brain. The proof is in the biochemical panorama. And while I sincerely believe that each of us chooses what we eat and how we treat our own bodies, there is something in science that shows the addictive properties of junk food.
I occasionally receive emails about this topic. Here's one I received a short while ago.
I know there are people who consider themselves addicted to sugar, so to speak. Some regularly offer their comments, and others write to me personally about the difficulty of breaking through that first "wall" on the way to a life free from rubbish. When you're addicted to sugar (or carbohydrates in general), even a “day off” can make you feel like a rabid demon looking for your next shot. Cutting all grains apart from sugar (as the grains quickly convert to glucose) will be critical to your success in this case. In fact, you probably can't get rid of sugar cravings in the long run without getting rid of the beans.
An interesting study presented at the Society for Neuroscience conference comes close to the biochemical reason for this. While the researchers observed mice that were fed a steady “junk food” diet (chocolate, cheesecake, bacon, sausage, etc.), they found that “animal brain reward circuits became less responsive” over time. Not surprisingly, animals began to exhibit "compulsive overeating habits". Even when subjected to light shocks, the animals were not intimidated when eating junk food and refused to eat healthier food when it was the only food available. In essence, junk food blunted their pleasure centers. As a result, they continued to search for junk food and eat in an attempt to trigger the reward trigger, but the neurological response was insufficient. This decrease in the response from the pleasure center, the researchers added, was "as if the rats became addicted to cocaine or heroin" (comforting, huh?)
Other studies have shown similar results. Using images of the human brain, the researchers found lower levels of the dopamine receptor (linked to reward and pleasure response) in obese people compared to individuals in the recommended weight range.