Insomnia and Weight Gain

A new study examined the link between insomnia and weight gain.

The study involved 14 men with primary insomnia and 24 healthy controls. It measured their levels of the “hunger hormones” leptin and ghrelin three times during one night of sleep.

Results show that men with insomnia had less total sleep time than controls. Leptin levels were similar between the two groups. Leptin helps to suppress your appetite and increase your metabolism.

But ghrelin levels were about 30 percent lower in men with insomnia. Ghrelin stimulates appetite.

So it would seem that insomnia lowers your risk of weight gain. Less ghrelin means you would be less hungry.

But this may not be the case. Lead author Sarosh Motivala of UCLA thinks that a change may occur during the day to increase appetite. Other studies show that sleep loss decreases leptin and increases ghrelin.

What is clear is that insomnia disrupts how the body regulates appetite.

"The current study shows that insomnia patients have a dysregulation in energy balance that could explain why these patients gain weight over time," Motivala said in a UCLA statement. “"This is an exciting finding because it highlights how diverse behaviors like sleep and eating are connected.”

Most people with insomnia have “secondary” insomnia. It occurs along with another medical problem, mental illness or sleep disorder. It also may result from the use of a medication or substance.

The men in this study had “primary insomnia.” This kind of insomnia is unrelated to another health problem. It is estimated that about 25 percent of people with insomnia have primary insomnia.

A 2008 study in the journal Sleep linked primary insomnia to low levels of a brain chemical. Results show that GABA levels are reduced by 30 percent in adults with chronic primary insomnia.

Learn more about the link between sleep and weight.