The systematic review examined data from 15 experimental studies - each of which examined whether or not providing information about other people's eating habits influences food intake or choices.
Writing in the Journal of the Academy of Nutrition and Dietetics, the team behind the analysis said they found consistent evidence that such social norms do influence food choice and intake.
Indeed, the team led by Dr Eric Robinson from the University of Liverpool revealed that when participants were given information indicating that others were making low-calorie or high-calorie food choices, it significantly increased the likelihood that participants made similar choices.
"It appears that in some contexts, conforming to informational eating norms may be a way of reinforcing identity to a social group, which is in line with social identity theory," explained Robinson.
"Norms influence behaviour by altering the extent to which an individual perceives the behaviour in question to be beneficial to them," he said. "Human behaviour can be guided by a perceived group norm, even when people have little or no motivation to please other people."
Study details
Robinson and his colleagues looked at data from a total of fifteen studies from eleven publications.
Eight of the studies examined how information about food intake norms influenced food consumed by participants, while seven other studies reported the effects of food choice norms on how people decide what food to eat.
In addition to finding that providing information about other people's eating habits influences the food intake or choices of others, the team also revealed that social norms influence the quantity of food eaten.
Indeed, the review noted that suggesting other people eat large portions increased food intake by the participants.
The team suggested the need to solidify our place in our social group is just one way social norms influence our food choices. The analysis also found that the social mechanisms that influence what we decide to consume are present even when we eat alone or are at work, whether or not we are aware of it.
"Given that in some studies the participants did not believe that their behaviour was influenced by the informational eating norms, it seems that participants may not have been consciously considering the norm information when making food choices," explained Robinson.
While the team cautioned that more research is needed, they did suggest that this type of study can help us understand the way people make decisions about food consumption and can help shape public policy and messaging about healthy choices.
"The evidence reviewed here is consistent with the idea that eating behaviours can be transmitted socially," said Robinson.
"Taking these points into consideration, the findings of the present review may have implications for the development of more effective public health campaigns to promote 'healthy eating.' Policies or messages that normalize healthy eating habits or reduce the prevalence of beliefs that lots of people eat unhealthily may have beneficial effects on public health."
Source: Journal of the Academy of Nutrition and Dietetics
Published online ahead of print, doi: 10.1016/j.jand.2013.11.009
"What Everyone Else Is Eating: A Systematic Review and Meta-Analysis of the Effect of Informational Eating Norms on Eating Behavior"
Authors: Eric Robinson, Jason Thomas, Paul Aveyard, Suzanne Higgs