Research May Explain Why Obese People Are Physically Inactive

Researchers have discovered a link between low dopamine levels and physical inactivity in obese mice. (Suzanne Tucker/

Researchers have discovered a link between low dopamine levels and physical inactivity in obese mice.

Are people obese because they are not physically active? Or are people physically inactive because they are obese? The results of a new study may explain how the brain affects or affected by obesity in humans.

Danielle M. Friend and Kavya Devarakonda and their team of National Institute of Diabetes and Digestive and Kidney Diseases researchers discovered a correlation between basal ganglia malfunctions and physical inactivity.

Published in the journal of “Cell Metabolism” Friend and Devarakonda explained that after examining obese mice they found dopamine levels were lower than regular mice.

Obesity is commonly linked to physical inactivity. Without moving around animals and humans are more likely to gain weight. However, Friend and Devarakonda hypothesized that low levels of dopamine in the brain is the reason why people are inactive and therefore, obese.

To test their hypothesis, researchers removed dopamine receptors in the brain of mice and found those mice exhibited less physical activity.

But, researchers found that physical inactivity did not actually lead to weight gain. In fact, even without the receptors they were not more likely to gain weight than the control group of mice. Furthermore, researchers argue that obesity causes physical inactivity and that physical inactivity does not cause people to become obese. In turn, diet has more of an impact on weight gain than physical activity.

Ultimately, researchers have discovered a biological connection between the basal ganglia in the brain and physical inactivity in individuals with obesity.

What is the basal ganglia?

The basal ganglia in the brain is responsible for movement, learning, and cognitive functions. Two major diseases associated with the basal ganglia include Huntington’s disease and Parkinson’s disease.

In addition, research has also shown that basal ganglia plays a role in motivation. In 2008 Liane Schmidt published a study in the “Journal of Neurology”. Her team discovered damage to the basal ganglia affected the self-driving behavior associated with motivation.