You are the company you keep. We’re sure you have heard the saying before — probably from your parents when you were growing up in an effort to make sure that you were surrounding yourself with good people and staying out of trouble. Or maybe they meant what and how much you eat.

A recent study published in the journal Social Influence surmised that how much food a person consumes can have an impact on how much another person eats. Researchers believe this is caused by social modeling, a psychological effect that would lead a person to eat less simply because the person they are dining with is eating a small amount of food.

“Internal signals like hunger and feeling full can often be unreliable guides,” says Lenny Vartanian, Associate Professor at the University of New South Wales’s School of Psychology, and the study’s lead author. “In these situations people can look to the example of others to decide how much food they should consume.”

Hunger pangs and satiety have less of an influence on how much we eat than someone eating in front of us. That’s an interesting thought in itself, that external factors are used more than internal factors when we decide how much we want to eat. People have the unique ability to affect change in another person by merely being around them. It’s not unusual to start using the same words or develop a habit your friend has simply because you’ve been around to see them do it. It’s also no surprise that such social influence could be prominent in dieting.

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