By Emily Reynolds

Scrolling through Facebook or Instagram, it can be easy to feel drawn in by the people you follow. Whether it’s the brands they’re buying, the things they’re doing or what they’re wearing, it’s not uncommon to want to follow suit — they’re called “influencers” for a reason, after all.

This isn’t only true of those who are paid to influence, however: those we know in “real life” and follow on social media can also impact the decisions we make. In a new study published in Appetite, Lily Hawkins and colleagues at Aston University find that what we think our online friends are eating can influence how healthy (or not) our own diets are.

The team asked 369 university students to fill in a survey about their perceptions of Facebook users’ food habits and preferences — how many servings of vegetables they believed an average Facebook user to eat every day, for example — and what they felt users’ food habits should be. They were also asked to rate how much they identified with the label of “Facebook user” themselves.

Next, a set of questions explored participants’ own eating styles: how able they feel to restrain themselves around food, how emotional their eating tends to be, and how often they engage in uncontrolled eating. They also filled in a food frequency questionnaire, which measured how often they ate various food types, and reported how many servings of fruit, vegetables and snacks they usually consumed.

Finally, the participants answered questions on their mood and appetite whilst completing the study, and on lifestyle factors like BMI.

The results showed that perceived norms amongst Facebook users did in fact predict how often participants ate fruit and vegetables. The more participants felt their Facebook friends were eating fruit and veg, the more they ate themselves. Meanwhile, participants’ consumption of unhealthy snacks and sugary drinks was influenced by how much they thought Facebook users should eat junk food.

How much Facebook users were perceived to like a particular food did not have a significant effect, however; participants’ own habits were only influenced by what they believed users were actually consuming, or should be consuming. That is, people tended to match whatever pattern of consumption they felt to be the norm.

Though our eating habits may be affected by perceptions of how other people are eating, the impact on our actual health may be limited: these perceptions were not linked to differences in participants’ BMI, a factor the team hopes to follow up on longer term.

The idea that online friends influence our lives so directly is compelling, but there were some notable limitations to the study. Firstly, only perceived norms were measured. What participants were actually seeing when they logged onto Facebook was ignored, but may prove to have an impact on what they were eating. And only 81% of participants were actually on Facebook — 19% didn’t have an account, so their perceptions of the average Facebook user may have missed the mark entirely.

Still, the study provides some insights into how perceptions of online norms influence the way we ourselves eat. It seems to differ depending on what’s being eaten. Healthy eating appears to be guided by other people’s behaviour, while our consumption of unhealthy foods is related to how likely we feel to be judged for our consumption — an effect that can be particularly potent online, the team suggests, where many of us feel a need for social acceptance.

This also suggests that social media could be used as a tool to “nudge” people into more healthy behaviours — potentially a useful public health intervention when it comes to encouraging healthy diets. But ensuring these nudges encourage positive behaviour, rather than shaming those who are more unhealthy, could be a factor worth further attention.

– Do perceived norms of social media users’ eating habits and preferences predict our own food consumption and BMI?

Emily Reynolds (@rey_z) is a staff writer at BPS Research Digest