A new study conducted by psychologists at Southwest University in Chongqing, China discovered that the brains of overweight individuals have a very different response to images of physical activity than the brains of average weight individuals.
Researchers surveyed 13 healthy women of an average weight, as well as 13 women who were considered overweight or obese. At the beginning of the study, the women completed two surveys, one which asked them to rate how important and desirable exercise was to them, and the other inquired about their attitudes towards exercise, and how they expected that exercise would make them feel.
Most of the overweight women rated exercise as very important, but also had negative feelings associated with it.
The research then exposed each woman to a series of images while laying inside a magnetic resonance imaging (MRI) machine, so that their brain activity in response to the images could be observed.
Ninety of the images showed people happily performing various forms of physical activity, and another ninety showed images of relaxed behaviors, such as sitting comfortably on a couch.
The participants were asked to imagine themselves doing the activities, and to move their bodies and hands to imitate the activities shown as much as was possible inside the MRI machine.
Results of the brain scans showed that during the exercise-related images, the brains of the overweight women had little activity in the regions that signal enjoyment. The regions that often lit up were the areas of the brain that deal with negative emotions.
When the women of average weight viewed the exercise-related images, their results were generally the reverse, signalling that they enjoyed what they saw, and were happy picturing themselves doing the same physical activities.
In the overweight women, the brain scans also showed that the region of the brain associated with “movement memory” did not light up, suggesting that one reason these women displayed negative emotions towards exercise might be that they did not know how to do it, and envisioned learning as a very difficult endeavor.
Researchers are unsure whether the obese women’s aversion to exercise was part of the cause of their weight gain, or if it stemmed from their weight gain. More research would have to be done to determine this distinction.
As far as what to do to combat the negative attitude towards exercise that most of the overweight women had, study leader Todd Jackson said, “Encourage people to pursue physical activities and exercise that they actually find pleasurable and might enjoy.”
Our attitudes and presuppositions of certain activities are very powerful, and can lead us towards or away from something, even if we have very little knowledge of the reality of it.
For this reason, if you are looking to achieve a healthy weight, but are daunted by the idea of exercise, start small, with an activity such as walking, preferably with a friend, but 
You may be surprised that it is actually quite enjoyable, and find yourself seeking out other various forms of physical activity.
-The Alternative Daily
Sources:
http://well.blogs.nytimes.com/2014/01/08/how-body-size-shapes-our-view-of-exercise/?ref=health
http://www.ncbi.nlm.nih.gov/pubmed/24366575