The Obesity Epidemic: What’s Causing It?

Obesity and over-nutrition are two of the most prevalent health problems facing Americans today. Although more people in the United States are trying diets and exercise programs than ever before, the problem seems to be getting much worse. In fact, 86% of Americans are expected to be overweight by 2030 (1). With that staggering number, there must be more to this problem than what initially meets the eye.



Over-nutrition, which is the excessive consumption of food, can have a variety of effects on the human body on the cellular and neurological levels. For example, consistent over-nutrition over a long period of time can result with oxidative stress in the mitochondria of neurons, which can then promote pathways that lead to the expression of TNFa, a transcription factor associated with over-eating (2). TNFa can also promote ER stress and inflammation, leading to overeating, which can in turn lead to more oxidative stress in the mitochondria and start the cycle over again (2). This promotes a positive feedback cycle causing the person to keep on eating more and more.



Artstract depicting mitochondrial dysfunction and ROS.


Obesity can also lead to changes in the brain’s physiology, such as insulin and leptin resistance, both of which can further promote over-eating and inhibit the pathways in the brain associated with appetite suppression (3). The large amounts of nutrients consumed during over-eating can also stimulate the brain’s reward system and trigger a large release of dopamine, making the brain susceptible to an over-eating addiction over time (3).


However, over-nutrition alone cannot explain the rise in obesity. Food additives may also contribute to the obesity epidemic. Over the last century, about 4000 new artificial chemicals and substances have ended up in our food, and not enough research has been done on these substances to determine what effects they may have on human physiology and behavior (1). Examples of these additives are:

  • Artificial colors
  • Emulsifiers
  • Added sugars
  • Artificial sweeteners
  • Pesticides, which end up in our food unintentionally.

Some research has shown that many of these compounds can contribute to obesity and related health problems. For example, MSG, a common food additive, was found to promote fat accumulation in rodents, and some organopesticides have been associated with the onset of Type II diabetes, (1).


Obesity is one of America’s biggest health challenges, and if we don’t change what we’re putting into our food, then this problem won’t go away any time soon.




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