A person’s weight can influence others' opinions about smell, apparently. A recent study conducted by scientists at the University of California, Los Angeles revealed that simply looking at images of heavier individuals could make a person perceive an otherwise neutral smell as unpleasant.

For the study, now published in the International Journal of Obesity, Dr. Ayako Tomiyama and his team asked participants to look at images of overweight or normal weight people, the Daily Mail reported. Afterward, volunteers were asked to smell a container of lotion tinted with different food colorings and asked to rate the smell. In actuality, all of the containers held the same fragrance-free lotion, but results revealed that the participants believed otherwise.

When images of overweight and obese people were displayed on the screen, participants gave worse ratings to the scent samples. Scientists previously observed a connection between feelings of disgust and perception of foul odors in a 2008 study, the Daily Mail reported. Interestingly, this trend remained the same even for overweight participants. In fact, the researchers wrote that this effect “was most strongly manifested by participants with higher BMIs,” suggesting that individuals with their own weight issues were some of the harshest critics of overweight individuals.

The researchers believe that this universal reaction could be explained by our subconscious disgust for obesity manifesting as a smell. Recent studies have suggested that discrimination against fat people may be partly due to the sight of obesity sparking deep-seeded fears of disease. A 2007 study found that just as rotten food can trigger nausea, the sight of an obese individual can trigger disgust. Being overweight is associated with ill health, and as reported by LiveScience, a healthy weight is a good indication of a strong immune system. Turning away from overweight people may be a natural defense against disease, especially when observing that these reactions were found to be the strongest in people who were most afraid of disease, BBC reported.

While the aversion of overweight individuals may be partly subconscious, experts urge that it’s this discrimination that can prevent many overweight individuals from making positive changes in their life.

“It undermines people’s motivation to diet and exercise,” said Angela Incollingo Rodriguez, one of the researchers working on the study. “If anything, stigma is a barrier to these lifestyle changes that people commonly use to lose weight.”

Source: Rodriguez ACI, Tomiyama AJ, Ward A. What does weight stigma smell like? Cross-modal influence of visual weight cues on olfaction. Nature. 2015.