If you’re having trouble getting motivated to get up off the couch, eat right and lose the extra pounds, you might want to consider the effect of those extra pounds on your brain. In fact, those pounds may be part of the reason why you are having a hard time motivating yourself to get off the couch in the first place.

Being overweight is linked to a variety of health issues such as heart disease, diabetes, hypertension and some cancers. But a high body mass index (BMI) can also be harmful to your brain.

Aging adults with higher BMIs experienced greater changes in C-reactive protein levels over time which predicted changes in cognition.

“The higher your BMI, the more your inflammation goes up. Prior research has found that inflammation — particularly in the brain — can negatively impact brain function and cognition,” said Kyle Bourassa, lead author of the study, in a statement. Cognition is a person’s ability to think, understand, reason, learn and remember.

Twelve years’ worth of data on the physical, social, and economic aspects of people over age 50 from the English Longitudinal Study of Aging were analyzed by University of Arizona researchers. They found that a person’s BMI affects both brain function and cognition, with inflammation as the likely cause.

When Bourassa and his co-author, psychology professor David Sbarra, looked at two different groups of people in the English study, they noted that both groups of aging adults with higher BMIs experienced greater changes in C-reactive protein levels over time which predicted changes in cognition.

C-reactive protein is a substance produced in the liver that rises as inflammation increases in the body. It is considered a marker of systemic inflammation in the body.

The study results only prove that there is an association between high BMI and cognitive decline, and does not prove that being overweight causes problems with cognition. To further connect the dots, more studies need to be done that look at the effects on inflammation and cognition when BMI is reduced.

Even among healthy older adults, some decline in cognitive function is normal, but the impact on a person’s quality of life can be frustrating and concerning. This type of research could lead to new areas of research and possible treatments.

Keeping your BMI in the healthy range is good for your overall health. BMI is a measure of body fat based on a person’s height and weight. You can determine your BMI here.

The study is published in Brain, Behavior and Immunity.