It’s not only what you eat — and how much — but also the company you keep when dining that may determine your obesity risk.

New research out of Australia finds that how much food your dining companion eats can have a big influence on how much you consume.

The findings, by the University of New South Wales, suggests a psychological effect — known as social modelling — leads people to eat less than they normally would if alone when their dining partner eats a small meal.

"Internal signals like hunger and feeling full can often be unreliable guides,” said lead researcher Lenny Vartanian, an associate professor at the UNSW School of Psychology. “In these situations people can look to the example of others to decide how much food they should consume."

The conclusions are based on an analysis of 38 studies, published in the journal Social Influence. The effect appears to be stronger in women than men, the results suggest.

"The research shows that social factors are a powerful influence on consumption. When the companion eats very little, people suppress their food intake and eat less than they normally would if alone," Vartanian said.

"If the social model eats a large amount, people have the freedom to eat their normal intake, or even more if they want."