In laboratory studies, exposure to social norm messages conveying the typical eating behaviour of others has influenced participants' ownconsumption of food. Given the widespread use of socialmedia, it is plausible that we are implicitly exposed to norms in our wider social circles, and that these influence our eating behaviour, and potentially, Body Mass Index (BMI).
This study examined whether four perceivednorms (perceived descriptive, injunctive, liking and frequency norms) about Facebook users' eatinghabits and preferences predicted participants' ownfoodconsumption and BMI. In a cross-sectional survey, men and women university students (n = 369; mean age = 22.1 years; mean BMI = 23.7) were asked to report their perceptions of Facebook users' consumption of, and preferences for, fruit, vegetables, energy-dense snacks and sugar sweetened beverages (SSBs), their ownconsumption of and preferences for these foods, and their BMI.
Multiple linear regression revealed that perceived descriptive norms and perceived frequency norms about Facebook users' fruit and vegetable consumption were significant positive predictors of participants' own fruit and vegetable consumption (both ps < .01). Conversely, perceived injunctive norms about Facebook users' energy-dense snack and SSB consumption were significant positive predictors of participants' own snack and SSB consumption (both ps < .05). However, perceivednorms did not significantly predictBMI (all ps > .05).
These findings suggest that perceivednorms concerning actual consumption (descriptive and frequency) and norms related to approval (injunctive) may guide consumption of low and high energy-dense foods and beverages differently. Further work is required to establish whether these perceivednorms also affect dietary behaviour over time.