The presence of an overweight eating companion may also influence your own eating pattern, suggests a new study.

Researchers at the Cornwell University conducted a study that shows how eating with an overweight diner can affect the eating habit of people with them.

The study involved 82 undergraduate student participants who were asked to eat salad and pasta lunch. The participants were randomly divided into four groups who ate their lunch on separate occasions. The researchers also included a professional actress who ate with the students.

The actress wore a so-called fatsuit, or overweight prosthesis that added 50 pounds to her weight, or did not wear the prosthesis at all. The professional actress served herself healthy food (a smaller portion of pasta and a bigger portion of salad) while wearing and without wearing the prosthesis. She also served herself unhealthy food (a bigger portion of pasta and a smaller portion of salad) with and without wearing the overweight prosthesis.

Participants in each of the four scenarios were asked to serve and eat after the actress. The study revealed that when the actress wore the overweight prosthesis the participants served as well as ate 31.6 percent extra pasta irrespective of whether the actress served herself more pasta or more salad.

When the actress served herself more salad, while wearing the overweight prosthesis, the participants served as well as ate 43.5 percent less salad.

The researchers suggest that people may eat more when eating with bigger and overweight dining companion as they forget about their personal health goals.

"This finding emphasizes the importance of pre-committing to meal choices before entering the restaurant," says Mitsuru Shimizu, Assistant Professor of Psychology at Southern Illinois University, Edwardsville, who is also the lead author of the study. "If you go into the restaurant knowing what you will order you're less likely to be negatively influenced by all of the things that nudge you to eat more."

The study authors also suggest that people can avoid this phenomenon by assessing the level of their hunger even before going to a restaurant and plan what to eat.

Brian Wansink, director of Cornell University's Food and Brand Lab, who is also the co-author of the study, suggests that people should look at the food menu beforehand and also select dishes, which suits their personal dietary goals. While going for a buffet, people should pre-commit and select modest portions of healthy food with personal dietary goals in mind.

The findings have been published in the journal Appetite.