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The Effects of Social Setting and Portion Size on Food Consumption Amount

Version 2 2024-06-02, 13:34
Version 1 2016-11-02, 12:09
conference contribution
posted on 2024-06-02, 13:34 authored by MCT Tan, Chris DubelaarChris Dubelaar, N Zlatevska
EXTENDED ABSTRACT How much a person eats has always been explained by an individual’s hunger and satiety level (Vartanian et al., 2008). In the 1960s, scholars first discovered non-physiological factors would better predict the amount of food a person will consume (Schachter et al., 1968; Stunkard & Koch, 1964). Existing literature shows that consumers’ food consumption behaviours are influenced by a number of distinctive contextual cues. These can be divided into personal contextual cues, consumption contextual cues, and food contextual cues. Individuals often seek norms of appropriateness from these contextual cues in eating events (Herman & Polivy, 2005). This research manipulates social settings and portion size, which are identified as important consumption contextual cues and food contextual cues respectively. Other contextual cues are kept constant by using an experimental method. Consumer preferences and marketing efforts are largely characterised by the advantages of larger portion size offerings (Dubois et al., 2012). Portion size is widely recognised as having a profound impact on the amount consumed (Zlatevska et al., 2014). In contrast, it is less clear as to what effect eating with others has on the amount consumed. Studies have reported people consumed both more and less as a result of eating in a group (Herman et al., 2003). Most food is offered in different portion sizes and consumed in a social setting. Whether or not the effect of portion size will be influenced by social setting remain unanswered. This research aims to better understand how portion size and social effects jointly affect the amount an individual is likely to consume. The research questions include: Will there be an interaction between portion size effect and social effect? Will personal characteristics moderate the effect of portion size and social influence? What is the effect of social influence when known context effects are controlled? These research gaps in the existing literature are important as both portion size and social effects are recognised as some of the most important contextual cues in the literature. These contextual cues were reported to have profound impact on an individual’s consumption amount. The understanding of the combined effect, its moderator, and directionality of these contextual cues is an important advancement in the current knowledge. Social effect was reported to be stronger for people with low self-esteem (McFerran et al., 2010). Hermans and colleagues (2009; 2012) show mixed results regarding correlations between restrained eating and amount consumed. Therefore, personal contextual cues are measured to examine moderation effect. In the face of the possible bi-directionality of social influence on the amount consumed by an individual, an experimental study design was used to keep various other contextual cues constant. A cover story was used in this research; participants signed up for a study that explores consumers’ choices of holiday destination. Participants were seated at a round table in a classroom, and were given some group activities related to the cover story to induce rapport. Eating was incidental to participating in this study. Participants signed up for the experiment on a voluntary basis and were awarded course credit. An experimental design with two (portion size: small, large) by two (social setting: alone eating, social eating) between subject design was used. This research consisted of two studies using different types of food. The food used in Study 1 was Arnott’s Nice cookies and the food used in Study 2 was MARS M&M’s chocolates. The cookies and chocolates in both studies were served in sealed, clear plastic containers that were opened for the participants by the experimenter. Each container was weighed before and after the experiment. In Study 1 (cookies), results show that individuals’ consumption is affected by the social setting (alone eating vs social eating), but not portion size. In addition, social effect is moderated by portion size effect. Restrained eating (but not self-esteem) moderated the effects of social setting on the amount consumed by an individual. In Study 2 (chocolates), results show that individuals’ consumption is affected by both the social setting (alone eating vs social eating) and portion size. Self-esteem and restrained eating both moderated the effect of portion size and social setting on consumption. In Study 1 (cookies), portion size effect was moderated by social effect. Given that portion size has been shown to have a profound and robust impact on the amount consumed (Zlatevska et al, 2014), portion size effect was moderated by the effect of social setting, which also has a great impact on consumption amount. This finding is consistent with fixed-unit effect reported in Davis et al.’s (2014) findings. They found that individuals consumed fixed units of food regardless of the unit’s size when individuals are eating in a group. However, in Study 2 (chocolates), both portion size and social setting had an impact on the amount consumed by an individual. The effects of portion size and social setting were independent and additive. The relationship between portion size and social setting differs in Study 1 and Study 2. This is explained by the difference in social visibility for different food type used in each study. The cookies that were used in Study 1 have higher social visibility compared to the small sugar coated chocolates used in Study 2. Therefore, the amount of cookies consumed by an individual is dependent on the social setting but not portion size. On the other hand, the impact of social effect and portion size effect in Study 2 are independent of each other. The finding of the difference in the relationship between portion size and social effects for Study 1 and Study 2 will help social marketers promote healthy eating lifestyles. This can be achieved by encouraging people to have their meals in a social setting; highlight the importance of portion size effect when eating small unit sized junk food in a social setting. We now know that social setting and portion sizes interact only when the consumption behaviour of participants is visible to others. When it is not visible, the two contextual cues reduce to their main effects only.



Hong Kong, China

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EN Other conference paper


Wan EW, Zhang M

Title of proceedings

Proceedings of the Asia Pacific Association for Consumer Research Conference 2015


Association for Consumer Research

Place of publication

Duluth, Minn.

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