What do obesity and diabetes have to do with brain health?

Have you ever heard the term “diabesity”?

It is a phrase used in lifestyle medicine and brain health circles, and also by Dr. Daniel Amen, to describe the connection his research has identified between obesity, type 2 diabetes, and brain health.

Dr. Amen is a psychiatrist, founder of Amen Clinics, and an internationally-renowned expert in brain health whose decades of SPECT imaging research on brain blood flow and activity have shown a consistent pattern linking obesity and type 2 diabetes with reduced efficiency in brain regions responsible for attention, memory, and self-control.

The term “diabesity” is used to capture that overlap between metabolic health and brain function, and to highlight that these conditions are not only physical but also neurological in their effects.

The reason this connection matters becomes clearer when looking at how the brain is powered. It depends on a steady supply of glucose and consistent blood flow to function properly. When insulin resistance develops, that system becomes less stable. The brain still receives fuel, but not in the smooth and regulated way it is designed to. That instability shows up in everyday thinking. Concentration becomes harder to sustain. Mental effort increases for tasks that once felt automatic. Processing speed can feel slower, even when nothing else in life has changed.

Inflammation also plays a role. Fat tissue, especially around the abdomen, releases chemical signals that circulate through the body. Over time, these signals can affect how brain cells communicate and how efficiently brain networks operate.

Research has also linked long-term metabolic dysfunction with structural changes in the brain, particularly in areas involved in memory and in the pathways that connect different regions. These changes help explain why cognitive performance can decline alongside obesity and diabetes.

This is not a fixed relationship. When metabolic health improves through nutrition, exercise, sleep, and blood sugar control, brain function often improves as well. The connection runs both ways, since brain function also influences appetite, decision-making, and long-term health behaviors.

Obesity and diabetes are often treated as physical health conditions. In practice, they are also closely tied to how the brain thinks, responds, and performs in everyday life.

Scotty