Obesity not only increases the risk of heart disease, diabetes and cancer but might also inhibit brain function.
Psychologists assessed the cognitive skills of obese people before and after weight loss surgery and found that patients scored higher on brain function tests after shedding some pounds.
The participants underwent gastric band surgery, an operation which reduces the size of the stomach and so the amount of food a person requires to feel full. This allows patients to avoid overeating as their appetite is vastly reduced.
Twelve weeks after the procedure the patients had lost an average of 50 pounds each.
Researchers at Kent State University in Ohio also used MRI imaging to study the brain structure of the participants. In particular, they examined nerve bundles that shuttle information through the brain. They found the fatty sheaths which protect the structures and speed up their function were often damaged.

Gastric band surgery decreases the size of the stomach and so a patient's appetite
Lead research fellow John Gunstad, said: “Doctors have known for a long time that being overweight is bad for your body.” The research shows that being overweight can also damage the brain: “especially,” he notes, “the parts of your brain most important for paying attention and learning new things.”
Prior to the surgery several individuals in the group achieved such low marks they could be classified as having a learning disability. The cognitive tests focused on information gathering and analysis, memory and verbal reasoning abilities.
The research is particularly relevant when considering the effects of childhood obesity on learning and development. As the number of overweight children worldwide continues to rise, significant changes to educational curriculum could be required to help them reach their academic potential.
The study’s results also support the use of weight loss surgery to treat obesity and hints at the reversible nature of cognitive impairment associated with the condition.
Gunstad, J., Strain, G., Devlin, M., Wing, R., Cohen, R., Paul, R., Crosby, R., & Mitchell, J. (2010). Improved memory function 12 weeks after bariatric surgery Surgery for Obesity and Related Diseases DOI: 10.1016/j.soard.2010.09.015