The sight of overweight people may influence your waistline, a new study suggests.

The results show people eat more junk food after viewing someone who is overweight, unless they consciously think about their health goals, the researchers say.

"Why do people often think back on a pleasant evening with friends and realize that they ate more and worse food than they wish they had?" the researchers, from the University of Colorado, write in the current issue of the Journal of Consumer Research.

If any of those friends carry a few extra pounds , just being in their presence could trigger what the researchers call a "negative stereotype."
"Seeing someone overweight leads to a temporary decrease in a person’s own felt commitment to his or her health goal," the researchers say.

In one study, researchers asked people who were walking through a lobby if they would take a quick survey. The surveys had photos of an overweight person, a person of normal weight, or a lamp. After completing the survey, the researchers asked respondents to help themselves from a bowl of candy as a thank you.

"People who completed the survey that included a picture of someone who was overweight took more candies on average than people who saw either of the other two pictures," the researchers write.

In subsequent studies, people who were invited to do a cookie taste test ate twice as many cookies or candy after seeing someone who was overweight. This was true even if the participants had a goal to maintain a healthy weight and were aware that cookies and candy can lead to weight problems.

Two main strategies served to counteract individuals' tendencies to overeat when in the presence of overweight individuals: thinking about health goals and being reminded of the link between eating and becoming overweight. For instance, when participants spent time writing about their health goals before viewing pictures of a normal weight person or an overweight person, they ate the same amount of cookies, regardless of which picture they saw.

Previous research has shown weight problems can spread through social networks . The researchers of the new study speculate their findings may explain, at least in part, why this occurs. "People see, both in person and in photos, the people with whom they have close social ties," they write.

The researchers have advice for people who are concerned about overindulging. "Thinking about personal health goals and reminding oneself of the undesirable effects of eating indulgent food at the time of possible consumption can help people avoid eating too much."

Pass it on: Seeing overweight people may cause individuals to eat more junk food.

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