Overeating linked to insulin resistance in the brain

A new study published in The Journal of Biological Chemistry has given insight into how overeating can cause obesity and type 2 diabetes.
Researchers from Mount Sinai School of Medicine, led by Christoph Buettner, MD, PhD, say they found that eating too much food impairs the ability of brain insulin to suppress glucose release from the liver and lipolysis in fat (adipose) tissue.
Lipolysis is a process that involves the breakdown of triglycerides in fat tissue and the release of fatty acids. Previous studies by Dr Buettner’s team showed that unrestrained lipolysis increases fatty acid levels, which can lead to obesity and the development of type 2 diabetes.
“Our recent studies suggest that once you overeat, your brain develops insulin resistance,” said Dr Buettner, who is the Associate Professor of Medicine (Endocrinology, Diabetes and Bone Disease) at Mount Sinai.
“Since brain insulin controls lipolysis in adipose tissue by reducing sympathetic nervous system outflow to adipose tissue, brain insulin resistance causes increased spillage of fatty acids from adipose tissue into the blood stream,” he explained.
According to the team, high levels of fatty acids increase glucose production in the liver, causing elevated blood sugars, and also trigger inflammation which, in turn, can increase the body’s resistance to insulin .
“It’s a vicious cycle and while we knew that this can begin with overeating, this study shows that it is really the brain that is harmed first which then starts the downward spiral,” Dr Buettner added.
The Mount Sinai researchers say they now plan to investigate ways of improving brain insulin function that could restrain lipolysis and improve insulin resistance .