You Exercise Less When You Think Life Isn’t Fair

People who have been the target of weight discrimination—and who believe the practice is widespread—are more likely to give up on exercise than to try to lose weight, according to a new study published in Health Psychology.

The online study of more than 800 Americans specifically looked at whether participants believed in “a just world,” or in this case, the belief that their positive actions will lead to good results. People who experienced weight bias in the past and didn’t believe in a just world were more likely to say they didn’t plan to exercise than those who did believe the world is just. In a separate part of the study, participants primed with anecdotes designed to suggest that the world is unjust were more likely to say they didn’t plan to exercise.

Experiencing discrimination leads some people to adopt a pessimistic view of the world, and they accept negative stereotypes about themselves, including the belief that they’re lazy, said study author Rebecca Pearl. “When someone feels bad about themselves and is applying negative stereotypes to themselves, they give up on their goals,” said Pearl, a researcher at Yale University, referring to a phenomenon known as the “why try” effect.

It’s an area of conflicting research. Some previous studies found that weight discrimination leads to weight loss, while others concluded that weight discrimination discourages exercise. Belief in a just world may be the factor that distinguishes between the two, Pearl said. People who think their exercise will pay off are more likely to try.

Because believing in a just world is key to losing weight, Pearl said that legislation and other public policy efforts could act as a “buffer against loss of sense of fairness.”

“It’s important for doctors to be aware of what people are experiencing, to know that these experiences might have real effects on people’s confidence,” Pearl said.