People who are obese tend to deter from walking long distances and climbing on steep hills by overestimating them. They also suffer a "vicious circle" of perception and behavior.
A study led by Dr. Jessica Witt, Colorado State University examined sixty-six people from Walmart by asking them to judge how far away a traffic cone on the road was. The cone was 25m away, but researchers found that individuals who were nine stone judged the cone to be 15m away while those who were 23 stone thought it was almost double that, at 30m.
Witt said that obese people see distances at least 10% further than those with an average weight, and people of all heights and weights "grossly overestimate" how steep hills are.
Participants were also asked to estimate distances and inclines, play virtual tennis, put a golf ball, and practice baseball. The performances were also analyzed using illusions.
They found that participants who put a golf ball performed worse when illusion made the hole look smaller and better when the hole was larger.
"We think that these perceptual biases can create a vicious circle for people with obesity. It is conscious perception of the world. But it's not based on conscious perception of the body or feelings of laziness," Witt said.