Home » News » Study: As Body Weight Increases, Brain Function Drops
Study: As Body Weight Increases, Brain Function Drops

Study: As Body Weight Increases, Brain Function Drops

A new brain imaging study of thousands of people reveals that a person’s body weight has a surprising impact on brain function. The results show that as body weight increases, all brain regions show a drop in activity and blood flow.

The good news is that brain function can improve when the brain is put in a healing environment through healthy eating, such as a healthy calorie-smart diet and regular exercise, said Daniel G. Amen, M.D., the study’s lead author and founder of Amen Clinics, one of the leading brain-centered mental health clinics in the United States.

The research, published in the Journal of Alzheimer’s Disease, is one of the largest studies linking obesity with brain dysfunction.

For the study, a research team analyzed more than 35,000 functional neuroimaging scans using single-photon emission computerized tomography (SPECT) from more than 17,000 individuals to measure blood flow and brain activity.

Low cerebral blood flow is the top brain imaging predictor that a person will develop Alzheimer’s disease. It is also linked to depression, attention-deficit hyperactivity disorder (ADHD), bipolar disorder, schizophrenia, traumatic brain injury, addiction, suicide, and other conditions.

“This study shows that being overweight or obese seriously impacts brain activity and increases the risk for Alzheimer’s disease as well as many other psychiatric and cognitive conditions,” said Amen.

The study findings showed notable patterns of progressively reduced blood flow in virtually all regions of the brain as they crossed several weight categories: underweight, normal weight, overweight, obesity and morbid obesity. These were seen while participants were in a resting state as well as while they were performing a concentration task.

In particular, brain areas previously linked to Alzheimer’s disease — the temporal and parietal lobes, hippocampus, posterior cingulate gyrus, and precuneus — were found to have reduced blood flow along the spectrum of weight classification from normal weight to overweight, obese, and morbidly obese.

Considering the latest statistics showing that 72% of Americans are overweight, 42% of whom are obese, the findings have significant implications for America’s mental and cognitive health.

“Acceptance that Alzheimer’s disease is a lifestyle disease, little different from other age-related diseases, that is the sum of a lifetime is the most important breakthrough of the decade,” commented George Perry, Ph.D., editor-in-chief of the Journal of Alzheimer’s Disease and Semmes Foundation Distinguished University Chair in Neurobiology at The University of Texas at San Antonio.

“Dr. Amen and collaborators provide compelling evidence that obesity alters blood supply to the brain to shrink the brain and promote Alzheimer’s disease. This is a major advance because it directly demonstrates how the brain responds to our body.”

This study highlights the need to address obesity as a target for interventions designed to improve brain function, whether it is Alzheimer disease prevention or attempts to optimize cognition in younger populations. Such work will be crucial in improving outcomes across all age groups.

Although the findings of this study are very concerning, there is hope. “One of the most important lessons we have learned through 30 years of performing functional brain imaging studies is that brains can be improved when you put them in a healing environment by adopting brain-healthy habits, such as a healthy calorie-smart diet and regular exercise,” said Amen.

Source: IOS Press

Study: As Body Weight Increases, Brain Function Drops

Traci Pedersen

Traci Pedersen is a professional writer with over a decade of experience. Her work consists of writing for both print and online publishers in a variety of genres including science chapter books, college and career articles, and elementary school curriculum.

APA Reference
Pedersen, T. (2020). Study: As Body Weight Increases, Brain Function Drops. Psych Central. Retrieved on November 30, 2020, from
Scientifically Reviewed
Last updated: 8 Aug 2020 (Originally: 8 Aug 2020)
Last reviewed: By a member of our scientific advisory board on 8 Aug 2020
Published on Psych All rights reserved.