The effects of social setting and portion size on food consumption amount.

Abstract

How much food a person eats has always been explained by an individual’s hunger and satiety level. Before scholars first discovered that non-physiological factors would better predict the amount of food a person will consume, physiological cues were the primary explanation as to how much a person consumed (Schachter, Goldman, & Gordon, 1968; Stunkard & Koch, 1964). The existing literature shows that consumers’ food consumption behaviours are influenced by a number of distinctive contextual cues. These cues can be divided into personal contextual cues, consumption contextual cues and food contextual cues. Among these contextual effects, social setting and portion size are identified as two of the most important contextual cues. Given that individuals often look for norms of appropriateness from these contextual cues in eating events (Herman & Polivy, 2005) and that individuals are always studied separately, the current research aims to examine the combined effect of portion size and social setting. In addition to this, the current research aims to examine social visibility and other personal contextual cues as the possible moderators of the portion size effect, the social effect and the combined effect of portion size and social setting. A quasi-natural research design was used in both of the experimental studies to manipulate the contextual cues that are of interest and to keep the other contextual cues constant. The findings from these two studies showed that consumers respond differently to the effect of portion size in different social settings. That is, the increased amount of food consumed by individuals due to a larger portion size differs when individuals are eating alone or eating in a group. In addition to that, the relationship between the effects of portion size and social setting is qualified by social visibility. When the social visibility is high, the portion size effect is moderated by the social setting. However, when the social visibility is low, social norms set by eating partners become vague and the effect of portion size and social setting become additive. The existing literature reports the social setting having opposing effects on food consumption and the distinctive areas of the social effect literature have prevented practical implications from being derived from the existing knowledge of the social effect. The findings in the current research advanced the existing knowledge of the social effect and contributed to improving the understanding of the practical implications of social effect. When the social visibility is high, social modelling is found among consumers eating in a group. However, consumers tend to reduce their consumption when they are eating in a group regardless of the social visibility. These findings were obtained from a series of experimental sessions where the eating duration in every experimental session was kept constant at five minutes. The current research concludes that social modelling coexists with social suppression (i.e. impression management) when consumers are eating in a social setting given that the eating duration is not overly long. Social visibility plays an important role in contextual effects. The influences of social norms prevail when the social visibility is high; consequently, consumers are less influenced by other contextual effects, such as the effect of portion size, self-esteem and restraint, than the social effect. However, when the social visibility is low, the consumption cues originating from the social norms set by eating partners become vague. The results of this study show portion size, self-esteem and restraint have strong influences on the amount consumed by consumers. Therefore, consumers who are eating in a group when the social visibility is low are influenced by the effect of portion size, self-esteem, and restraint as well as the social setting. In addition to this, the effect of portion size is moderated by consumers’ self-esteem and restraint level when the social visibility is low but not when the social visibility is high. This is due to the weakened social effect caused by vague social norms in low social visibility conditions. When consumers are eating from a small portion in low social visibility condition, consumers with low self-esteem and consumers who are more restrained consume more food. While self-esteem moderates the effect of the social setting when the social norm is vague due to low social visibility, restraint moderates the effect of the social setting regardless of the social visibility. This shows that restrained consumers are less influenced by the social effect. Importantly, these findings provide evidence for theoretical discussions and new research avenues. The portion size effect has been shown to be robust and methods such as educating consumers about the adverse risk of portion size failed to reduce the negative consequences of the portion size effect. The current research shows that the portion size effect is moderated by the social setting in high social visibility conditions. Therefore, one of the largest theoretical implications of the current research is the finding of the possibility of reducing the adverse effect of the portion size through social eating. Another important theoretical contribution is the finding of the prevalence of the social effect over the portion size effect and that the effect of social setting is moderated by social visibility. Collectively, these have contributed to addressing the existing knowledge gap and enabled the theoretical implications of current findings. These important findings could make a large contribution to the food industry, where food manufacturers can continue to reap the benefits of large portion size offerings while reducing the general well-being drawbacks to consumers through the identified moderators. Not only would this reduce the negative reputation that food marketing currently has, social marketers and public policy makers can also use. these findings to promote a healthier lifestyle to consumers.

Date of Award	10 Jun 2017
Original language	English
Supervisor	Peter Dubelaar (Supervisor) & Natalina Zlatevska (Supervisor)