Obesity rates are skyrocketing, and there is no denying that it is a large problem for our country. There are many contributing factors that lead to the development of obesity. As our diets has become more and more heavily composed of fat, sugar, and carbs, our bodies are undergoing changes that are leading to extreme health problems, including Type 2 diabetes and Obesity. Processed foods have become more addictive, because of the high amounts of fat, sugar, and additives they contain. These components in our food are altering the normal signaling within our bodies, leading to the development of chronic metabolic illnesses.
The Role of Insulin
Insulin is a key factor that our bodies use in maintaining energy homeostasis. Insulin is used to regulate the amount of energy your body needs and expends.
After we eat, insulin is released into the bloodstream, causing the food (glucose) that we consumed can be absorbed into our cells and used for energy. Insulin also acts in the brain where it binds to its receptors on neurons in the hypothalamus, causing an anorexigenic response. The anorexigenic response is one that lets you know you are full and should stop eating.
Insulin and Reward
Insulin also acts on dopaminergic neurons in the midbrain (involved in the reward pathway) The desire to eat is not only driven by the body’s current nutritional state, but also by the rewarding aspect of food. Reward- based eating behavior is likely linked strongly with obesity because the signaling in these circuits can eventually override the signaling in the hypothalamus. Insulin is able to change reward-related behavior by decreasing sucrose intake and conditioned preference for high-fat food. Therefore, insulin signaling is involved with the regulation of energy homeostasis and food intake in these neurons as well. When fed, insulin signals for you to stop eating for pleasure, and attempts to control your food intake.
Insulin Defects= Bad News
Eating a high saturated fat diet causes disruptions in the insulin signaling pathway, thus interfering with energy homeostasis and the sending of messages to stop eating. This leads to inflammation in the brain and causes lots of stress in the cells. A cascade of inflammation begins; making the insulin receptor unable to continue the cascade that is supposed to occur once insulin is bound. This particular problem is what is known to be Type 2 diabetes. Insulin is present, and so is its receptor, but the rest of the pathway is dysfunctional.
Effects of Processed Foods
Since processed foods contain fat and sugar than we are not meant to consume, when we them, we start to crave them because the chemicals, fats and sugars they contain are causing chemical changes in our brains. This can lead to insulin resistance and the dopamine reward pathway can eventually override the hypothalamus, since we develop such a strong desire to eat these foods. It is a cascade that can very quickly get out of control and manifest into what is essentially brain disease, presenting itself visually as obesity.
Treatment
Hedonic feeding, the term used to describe the drive to eat to obtain pleasure, without actually having an energy deficit, is the type of hunger that most weight-loss programs are targeting. They are focused on relieving cravings, instead of targeting the hypothalamus and the inflammation/stress that occurs there due to the insulin resistance that occurs. There are several different medications available that can be used to treat food cravings in order to lose weight. Gastric bypasses are also common and effective. They bypass most of the stomach so that the individual will feel full much faster and not physically be capable of eating any more.
Regulations?
Since it seems like the cause of this obesity problem all comes back to the ingredients in the food we are eating, shouldn’t there be more restrictions and regulations on what companies are allowed to put in processed foods? Other countries have more restrictions on certain food preservatives and contents that they are allowed to include, and overall this seems to be an intelligent, logical idea. Until any laws are passed, however; all that we can do to steer clear of Type 2 diabetes and obesity is to eat whole, nutritious foods and get plenty of exercise. Food companies can tempt us all they want with the high-fat, high-sugar foods they process, but we must look out for our health and do the best we can to resist these foods that will give us brain disease.
For more information related to insulin signaling, energy homeostasis, and glucose metabolism, please visit:
https://moodle.cord.edu/pluginfile.php/625315/mod_resource/content/0/2013%20CNS%20insulin.pdf
Obesity: More Than Meets the Eye
