Overweight people who said they’d experienced discrimination based on weight were more than twice as likely to be obese four years later than people who didn’t mention such discrimination. And those who started out obese were three times more likely to remain so if they’d been harshly targeted because of their weight. Other types of discrimination showed no effect on weight.

Sutin’s , published in the latest issue of the online journal PLOS One, wasn’t designed to get at why weight discrimination led many fat people to pack on even more pounds. But other research suggests that increased rates of depression, emotional eating and low-self esteem likely play a role. So does increased stress (and the associated hormonal surges that can trigger even more hunger and eating), as well as the avoidance of exercise.

“If someone’s mean to you at the gym because of your weight or acts like you don’t belong there,” Sutin says, “you’re less likely to go back.”