The study, published Thursday in the journal Obesity, looked at the levels of a stress hormone called cortisol in locks of hair gathered from participants.
"It's providing glucose to the brain, keeping things going during a stressful event," Jackson said. "It also plays a huge role in metabolism, body composition and the accumulation of body fat."
The release of cortisol is triggered by receptors that are densely located in visceral fat tissue, the type that surrounds our organs, which may explain its association with weight gain and loss.