Reprint of: Eating like you are overweight: the effect of overweight models on food intake in a remote confederate study

The role of perceived descriptive and injunctive norms on the self-reported frequency of meat and plant-based meal intake in UK-based adults

Perceived social norms refer to beliefs that people hold about what other people do (descriptive norms) and approve of (injunctive norms), and are associated with food intake. However, less is known about whether perceived social norms are associated with meat and plant-based meal intake. Using a cross-sectional survey design 136 participants (aged 19-66 years, mean age = 39.63, SD = 12.85 years, mean BMI = 25.77, SD = 5.30, 80.9 % female, 77.9 % omnivores, 22.1 % flexitarians) answered questions about how frequently they consumed meat and plant-based meals, and how frequently they perceived people in their social environment to consume (perceived descriptive norms), and approve of consuming (perceived injunctive norms) meat and plant-based meals. Perceived descriptive and injunctive norms were positively associated with participants' frequency of meat intake: participants ate meat more frequently when they perceived their significant other to frequently eat meat (descriptive norm), and when they perceived their significant other and friends to approve of (injunctive norm) frequently eating meat. Perceived descriptive norms were positively associated, but injunctive norms were negatively associated with participants' frequency of plant-based meal intake: participants ate plant-based meals more frequently when they perceived their extended family, friends, and significant other to frequently eat plant-based meals. However, participants ate plant-based meals more frequently when they perceived their extended family to approve of less frequent plant-based meal intake. These results suggest that different social groups may be important for meat and plant-based meal intake, with significant others and friends appearing to be important reference points for both food types. Further research examining the contexts in which the different social groups influence eating behaviour would be of value.

Social Modeling and Eating Behavior-A Narrative Review

Social modeling of eating is the adjustment of the amount of food eaten to the intake of the accompanying person. In this paper we provide a narrative review of literature on social modeling of eating with a particular focus on recent studies. Firstly, we describe the structure of a typical modeling experiment. Secondly, we present a variety of research in this field: experiments with various types of confederates, experiments aimed at the evaluation of the influence of gender, partner’s body weight, type of food, hunger, personal characteristics, etc. Thirdly, we present practical implications of this knowledge. The common conclusion is that social modeling of eating occurs in different situations and consumption is adapted to the standards established by the eating partner, but is not their direct reflection. Social influence of eating is not restricted to "artificial" laboratory situations; social modeling and social norms manipulations may be used to change people’s dietary practices, especially in children and young adults. Within the home environment parental modeling has been shown to promote children’s snacking and fruit and vegetable consumption. Social modeling may be used in nutrition interventions aimed at the improvement of children’s diet and in obesity prevention programs.

The effectiveness of a social media intervention for reducing portion sizes in young adults and adolescents

Objective

Adolescents and young adults select larger portions of energy-dense food than recommended. The majority of young people have a social media profile, and peer influence on social media may moderate the size of portions selected.

Methods

Two pilot interventions examined whether exposure to images of peers’ portions of high-energy-dense (HED) snacks and sugar-sweetened beverages (SSBs) on social media (Instagram) would influence reported desired portions selected on a survey. Confederate peers posted ‘their’ portions of HED snacks and SSBs on Instagram. At baseline and intervention end participants completed surveys that assessed desired portion sizes.

Results

In intervention 1, undergraduate students (n = 20, mean age=19.0 years, SD=0.65) participated in a two-week intervention in a within-subjects design. Participants reported smaller desired portions of HED snacks and SSBs following the intervention, and smaller desired portions of HED snacks for their peers. In intervention 2, adolescents (n = 44, mean age = 14.4 years, SD = 1.06) participated in a four-week intervention (n = 23) or control condition (n = 21) in a between-subjects design. Intervention 2 did not influence adolescents to reduce their reported desired portion sizes of HED snacks or SSBs relative to control.

Conclusions

These preliminary studies demonstrated that social media is a feasible way to communicate with young people. However, while the intervention influenced young adults’ reported desired portions and social norms regarding their peers’ portions, no significant impact on desired reported portion sizes was found for HED snacks and SSBs in adolescents. Desired portion sizes of some foods and beverages may be resistant to change via a social media intervention in this age group.