Does Obesity Have Effects On the Brain?

Although obesity can cause medical problems involving heart disease, diabetes, sleep apnea and depression, can it affect cognitive functioning as well? According to a research study recently broadcasted in Neuropsychology, that might actually be true. John Gunstad of Kent State Universoty and Kelly M. Stanek of the University of Alabama directed a team of researchers studying the interaction of BMI and cognitive performance throughout the human lifespan. Their conclusions have worrying problems for the present obesity epidemic as well as the alarming rise in dementias cases amongst older adults.

Based on prior studies, obesity has been related to increased danger of Alzheimer’s disease and stroke. Weight gain has also been linked to a continuing decline in cognitive functioning even when dementia is not in play. Neuroimaging studies of morbidly obese people (BMI bigger than 40) propose that they are at a larger risk for brain deterioration- however these outcomes are still debatable for younger individuals. As people get older however, they become more susceptible to brain-related illnesses which may make the consequences of obesity even more essential.

In their latest study, Stanek, Gunstad, and their collaborators studied data collected from the Brain Resource International Database (BRID) as well as data taken from a national study of morbidly obese people having bariatric surgery to aid in weight loss. In total 732 people varying in age from 18 to 88 and with BMI score ranging from 19 to 75 were used in the study. As well as medical history, the researchers also looked at how the people in the study responded on different analyses of cognition, including memory, attention and decision-making.

Like the researchers predicted, age was inversely linked to performance on most of the cognitive tests. Decreased attention, fine motor speed, and processing speed was also a connected consequence to obesity. However, the relationship between BMI and other cognitive capabilities seemed to be more complex. Even though the overall correlation between BMI and executive functioning was not substantial, it did become a factor when age was brought into the picture. According to the results, executive functioning shortages were greater for older adults who were obese than for older adults who had a lower BMI. When factors such as medical history were taken into account, these results were still significant.

Overall, these findings indicate that obesity can increase the risk of different cognitive problem as individuals age. The interaction between age and BMI in reduced executive functioning seem especially important since both aging and obesity have separate effects on brain structure and cognition. As people get older, they become more susceptible to different issues affecting brain functioning than when they were adolescents.

The relationship between cognitive damage and obesity is not necessarily limited to older adults however, since research has found cognitive problems in severely obese younger individuals as well. Since there have been quite few research studies dealing with obesity and brain functioning so far, the definite connection between BMI and cognition is still uncertain.




Picture from:



3 thoughts on “Does Obesity Have Effects On the Brain?

  1. Francis Patrick Cotter

    A third confounding variable may have an effect on the results you refer to in this study. Obesity can obviously have a connection with a lack of exercise. Exercise has shown, such as in this study (, to improve brain function. Therefore, it can be concluded that brain function is more affected by the lack of exercise that is related to obesity rather than the sole influence of obesity on brain function.

  2. mzm6020

    Very nice post! It is really interesting that the results differed from age to age, but I might know a reason for that. See, as people age, cognitive functions follow a gradual rate of diminishing grey matter. This grey matter is used for memory, learning, and many cognitive functions. This might be a very big confounding variable for the results that you researched on. If you test the musical capability of a 50 year old piano player, or a 25 year old piano player, there will be great differences because the frontal cortex of the brain may not have as much grey matter. This is also applicable for BMI and cognitive functions. Age is a great indicator for differences in brain activity! Here is a link that explains more about it!

  3. Amily Zhuang

    I recently just posted a blog solely to educate people on obesity and I am glad that I came across your article because it dove into detail about the effects it has on your body. It’s absolutely crazy to me that obesity has such negative impacts on the body and brain. I’m sure the insecurites also cause mental illnesses such a depression and that’s a whole other blog that can be made.

    Here is a video of a 10 year old wth life threatening obesity that I think would help your article. It shows the hardships of someone who is obese.

Leave a Reply