Here's a tip for individuals trying to cut down on unhealthy food intake: avoid dining with an overweight person.

A newly published study in the journal Appetite reveals that while there are a number of factors that could affect the way a person eats, the body mass index, or BMI, of dining companions could also influence his food choices and the amount of food he eats.

Earlier research suggest that diners can be affected by the sight of overweight people and high-calorie foods, and it is partly because of this that Mitsuru Shimizu, from the Southern Illinois University-Edwardsville, and colleagues decided to investigate the effects of having an overweight diner around during mealtime.

For their study, the researchers had groups of 82 college students serve and eat a lunch of salad and pasta after observing a female confederate, who drew attention to herself by speaking loudly before serving lunch to herself.

In four of the lunches, the woman, who had a normal weight of 126 pounds, wore a prosthesis that made her look overweight. Sometimes the woman had more salad than pasta, considered a healthy meal, and in other times ate more pasta than salad. The researchers then measured how much of the pasta and salad did the participants consumed they have eaten.

Shimizu and colleagues found that the presences of an overweight companion increased unhealthy food intake. The participants ate 31.6 percent more pasta when the woman worse her fat suit no matter that she served herself with healthy food. The participants ate 43.5 percent less salad even when they saw the woman serving herself healthily.

"Results demonstrated that regardless of how the confederate served, participants served and ate a larger amount of pasta when she was wearing the prosthesis than when she was not," the researchers wrote. "In addition, when the confederate served herself healthily, participants served and ate a smaller amount of salad when she was wearing the prosthesis than when she was not."

The researchers said that the findings of the study suggest that people may eat more unhealthy food when they eat with an overweight person. There are certain practices, however, that can prevent such incidents from happening such as planning one's meal ahead of time before going out to dine with somebody.

"This finding emphasizes the importance of pre-committing to meal choices before entering the restaurant," Shimizu said. "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."