On a diet? Be careful what your friends eat.

NEW YORK (Reuters Life!) - Dieters beware. You might be watching what you eat but if a friend next to you is tucking into a calorie loaded snack you could be in trouble.

An international study found that watching someone eat a snack caused the viewer to be inclined to eat the same thing.

The study, published in the April issue of the Journal of Consumer Research, set out to look at the impact of mimicry on product consumption and found people automatically mimicked other people's eating habits.

The study was based on how 147 undergraduates at Duke University in Durham, North Carolina reacted when watching someone else talking while dipping into one of two bowls in front of them -- one filled with goldfish crackers and one with animal crackers.

"A person who views someone else's snacking behavior will come to exhibit a similar snack selection pattern," the researchers from Duke University, University of Maryland and the University of Amsterdam said in a statement.

"This suggests that preferences may shift as a result of unintentionally mimicking another person's consumption behavior."

In the study, participants sat in private lab room and watched a video of someone describing a series of advertisements while occasionally taking goldfish or animal crackers from a bowl.

Although bowls of both goldfish and animal crackers were present, the person in the video only took from one bowl.

The viewer also had a bowl of each of the snacks but those who watched a person eat goldfish crackers took from the goldfish bowl 71 percent of the time.