Friday, April 24, 2015

The Long Term Effects of Obesity

If you are like me, then we'd probably agree that there are five major food groups: Hamburgers, French fries, pizza, ice cream, and Chipotle. Unfortunately, this kind of lifestyle is generally frowned upon, as it’s prevalence and has led to the widespread epidemic of obesity. Obesity is described as a disorder with an excessive and unhealthy amount of body fat that is usually brought on by an unhealthy diet and a lack of physical activity. America is facing a widespread epidemic of obesity, with increased levels of the disorder within the past few years. Obesity has spiked most noticeably in children, where a third of children in the United States are estimated to be overweight, 15% of which are categorized as obese.

Obesity can lead to a myriad of health problems that begin developing at an early age in children, including diabetes, cancer, cardiovascular issues, liver disease, and depression. Obese individuals will have a buildup of plaque in their bloodstream, leading to difficulties in the heart functioning properly. Obese people generally have symptoms of increased blood pressure and increased risk of heart attack and stroke. One notable complication from obesity is insulin resistance. Insulin promotes the absorption of glucose from the bloodstream to the body cells. However, in obese individuals, insulin will generally stay in the bloodstream, as the body cells insulin receptors do not function properly, leading to type II diabetes. The immediate effects of obesity are well document and children with obesity will likely have continual health problems as they grow older, but the long-term implications of obesity are still being researched, especially how it affects them cognitively.

The Full Insulin Pathway that can lead to Obesity

A recent study done by Wang et. al. looked to examine the long-term impact of obesity and insulin resistance and how it affects cognitive function later in life, even once a child has switched over to a healthy lifestyle. To do this, researchers compared two groups of mice, one with a regular diet, and one that had a high fat diet for the first fifteen weeks and a regular diet for the next 16 months. The rats on the high fat diet were severely obese after the initial fifteen weeks. The rats were then tested on their cognitive ability based on a memory test and the Morris Water Maze (MWM). The MWM is a small water filled maze, where the mice are trained on how to escape, and then tested on their own to see their spatial cognitive abilities. Other molecular studies were done to see if there were any genetic changes in the mice with the fatty diet.

The results of this long-term study were that the mice with the high fat (HF) diet had significant difficulty in spatial memory after aging. These results suggest that insulin resistance and obesity as a child could lead to poor cognitive development as one grows older. Studies also indicated that these high fat diets lead to less effective neurons and poor synaptic function. Researchers saw changes in peptide and protein function due to build up of plaque and misfunctional production of certain proteins. Specifically, parts of the hippocampus in HF mice showed limited stimulation when electrically probed, when the control mice had high levels of activity. Despite only being obese during their childhood, it seems as if that kind of lifestyle had serious long term ill effects on the mice that change the physical composition of their brain and how it functions when stimulated.

Results of the studies comparing the control rats with the HF ones. Graphs examine the proficiency of both groups in performing the spatial memory testing, among other tests.

These results can be compared to humans and show the dangers of childhood obesity. While the immediate health threats brought on by obesity are well known, the long term consequences even after reaching a healthy life style are still being uncovered. An obesity occurrence and insulin resistance during childhood development can severely and irreversibly damage and modify the brain, and can increase risk of memory loss diseases such as Alzheimer’s in old age.

This study really highlights the need to further emphasize the need for healthy life style choices and an increased awareness of public health for our youth. Children are still developing beings and are especially susceptible to disruptions in that development, especially with their brain. Being careful with what you eat is important at all ages, but its society’s responsibility to make sure children are healthy to avoid long term consequences.


Wang, J., Freire D., Knable L., Zhao W., Gong B., Mazzola P., Ho L., Levine S., and Pasinetti G.M. (2014) Childhood and adolescent obesity and long-term cognitive consequences during aging. The Journal of Comparative Neurology. 523: 757-768

"Obesity: MedlinePlus." U.S National Library of Medicine. U.S. National Library of Medicine, 1 Oct. 2014. Web. 24 Apr. 2015. <>.


  1. In terms of the rats preforming poorly on the Water Maze and that being a measure of their cognitive abilities, could that not just be a function of the poor physical condition that the mice are in? I am curious because the water maze does have a highly physical aspect to it that could cause issues in assessing neurological changes. Also this article makes me wonder about the inactivity leading to brain damage article by Jodi which seems like these two could be related in that a high fat diet combined with lack of activity can damage the brain severely.

  2. Interesting that obesity can actually contribute to cognitive impairment, I never would have suspected that. We clearly need to improve our health education and prioritize physical education early on.

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  4. Obesity is one of the main concerns of the world today because of the health problems it causes while an individual is actually obese. I feel like no one really thinks about the long term effects of obesity because they think that once they lose the weight they're fine. The fact that obesity can cause long term cognitive impairment even after the individual has switched to a healthy lifestyle shows that not only do we need programs to help obese people, we need preventative programs as well.

  5. Being Canadian, this is interesting because it is true you come to States and everything is cheaper and so many of the serving sizes are much larger than in Canada. I go help out at a local elementary school and I see so many overweight kids and I don't understand. Is it because the unhealthy foods are cheaper and require no effort to prepare? I feel like more people need to be aware of all the side effects, short and long term. Society needs to do a better job at addressing this problem. Many people probably do not realize that there can be lasting effects even once they chose to lead a healthy life.

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  7. I'm sure we've all heard the saying, "it's not what you eat, but how you eat," but I think this article does a great job of highlighting that WHAT you eat is in fact very important. Again, as an athlete I tend to eat junky food carelessly because I know that I will burn it off later. I found it really intriguing how even after the high fat diet mice began to be fed with a regular diet, they still experienced effects of their unhealthy diet long after.
    Although, I am not obese, I wonder how the my poor diet will effect the efficacy of my neurons and synaptic function.

  8. Along a similar line, it seems likely the chemicals, additives and preservatives commonly found junk may also contribute to cognitive functioning. Studies have already presented evidence suggesting a correlation between food chemicals and additives and behavioral issues, especially in children with neurodevelopmental disorders such as ADHD. So not only are junk foods a concern for cognitive function because of there high fat content, they also present a further threat with all the chemicals added.