35% of adults age 20+ are obese. This is becoming a severe problem, especially in the United States. What is causing this spike in obesity? How does obesity become an issue in the body? I would like to discuss the background related to this topic.
Inflammation and obesity:
The issue with obesity usually begins with the body becoming insulin resistant. The resistance is caused by overnutrition. Overnutrition or overeating causes stress in the body, particularly in the organelles like the mitochondria and the endoplasmic reticulum which are devoted to breaking down the foods we eat and creating proteins in the body. In overnutrition, these organelles become overwhelmed which leads to activation of the JNK pathway. This is a pathway normally implicated in the stress response, therefore, it acts to inhibit the insulin receptor substrate and causes inflammation. This in turn leads to more inflammation and more shutting down of the insulin receptor and insulin receptor substrate.
The shutting down of the insulin receptor and insulin receptor substrate makes it increasingly hard for insulin in the body to do its job. Normally, when we eat food, insulin is released in the body and it signals POMC and AgRP neurons in the hypothalamus which tell the body to stop eating. However, in overnutrition the shutting down of receptors causes the body to not react to the insulin being released. The beta cells in the pancreas are responsible for making insulin and as insulin resistance begins they are able to make increasing amounts of insulin to try to combat the resistance. However, at some point a threshold is reached and the body cannot produce enough insulin. This leads to hyperinsulinemia and usually the onset of type 2 diabetes.
Onset of obesity:
Eventually, the insulin is not sufficient to produce a response in the body. Therefore, the body cannot recognize that you’re consuming too much food and will constantly signal to keep eating. The stress continues and just potentiates the problem and causes obesity. This is just some of the pathology behind obesity. With the excess of food and availability of food that we have now, it helps to explain the reason why obesity is such a problem right now. Finding a solution is increasingly important as obesity and type 2 diabetes have very negative impacts on the body.
Onset of Obesity from: http://www.life-enhancement.com/images/LEM1211chart211.gif
For more information about obesity and its pathology read:
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