Obesity as a Brain Disorder
Have you ever thought, “If I just had more willpower I could resist all the unhealthy foods I tend to eat”? I’m sure you have heard someone recommend that if you want to become healthy just eat more fruits and vegetables. And I bet you have even heard someone tell another to simply give up something (carbs, desserts, fats, etc.) in order to lose weight. These ideas and suggestions seem true; we do not argue them. More veggies and less dessert will help with weight loss. However, the idea that more will power is the key may not necessarily be correct. In the article I read for my neurochemistry class this week, we learned about obesity as a brain disorder. In the abstract, the first paragraph of the article, the author refers to over nutrition as a biological trap independent of the initial trigger. To me, this connotation has serious implications toward how obesity is treated and perceived.
“Biological Trap” Studies in Rats
As a simple and comprehendible model, studies with rats, has offered good insight into habituated choices of diet. Some results of such studies include:
- Early exposure to fatty food predisposes the animals to favor a high fat diet
- Animals fed with a high fat diet became insulin and leptin resistant and had high blood pressure
- Prenatal and postnatal exposure of the mother to a high fat diet increased the offspring’s weight gain and influenced their dietary habits
- Continuous access to food high in fat leads to more weight gain
These results are significant, even when relating it to humans, because the rat is a very simple model. The results contain no influence from cognition (as they would in humans) or cultural and social influences. The simplicity allows us to see the basic ideas at work in the human body without the confusion of human consciousness. These are the risk factors and conditions, along with some consequences of being predisposed into falling into the biological trap that is obesity.
Activity in the Obese Brain
To explain further what perpetuates the cycle of over nutrition and the biological trap, I want to discuss the brain activity of an obese individual in comparison to a healthy weight individual. Obese individuals have a greater response to the presence of food. Obese individuals have a higher enhancement of anticipated reward compared with lean individuals. Furthermore, the obese brain has less dopamine receptors making the feeling of fullness and pleasure much less after eating a meal than in lean individuals. This is shown in the image below. The obese brain has lighter colored pleasure centers, showing less dopamine receptors and reward activity after a meal.
Willpower Might Not Be Enough
To hammer home the idea that obesity is a brain disorder and not a lack of will power I will direct you to the next image below that I took directly from the article I read.
I am not posting the image because I hope to explain every detail of the science behind obesity. I wanted to share the image because I think that it shows just how complex obesity is. Many other symptoms that go along with obesity do not receive enough attention. They include depression, memory, and learning deficits. Furthermore, this image shows the web of connections that make up the disorder. Each component should be taken into consideration, especially when one feels as if obesity is a moral, cultural, or personal issue. While these components do have influence in the disorder, the key to treating and preventing obesity in America, a country saturated with unhealthy and fatty foods, is understanding the brain science behind the disorder. This will lessen the negative connotation and perception of obesity while helping narrow and focus treatment toward each individual.
