Served Portion Sizes Affect Later Food Intake Through Social Consumption Norms

Abstract

Portion sizes of commercially available foods have increased, and there is evidence that exposure to portion sizes recalibrates what is perceived as ‘normal’ and subsequently, how much food is selected and consumed. The present study aims to explore the role of social (descriptive and injunctive) and personal portion size norms in this effect. Across two experiments, participants were either visually exposed to (Study 1, N = 329) or actually served (Study 2, N = 132) a smaller or larger than normal food portion. After 24 h, participants reported their intended consumption (Study 1) or served themselves and consumed (Study 2) a portion of that food and reported perceived portion size norms. In Study 1, visual exposure to portion size did not significantly affect intended consumption and perceived portion size norms. In Study 2, participants consumed a smaller portion of food when they were served a smaller rather than a larger portion the previous day, which was mediated by perceived descriptive and injunctive social (but not personal) portion size norms. Results suggest that being served (but not mere visual exposure to) smaller (relative to larger) portions changes perceived social norms about portion size and this may reduce future consumption of that food.

That’s My Cue to Eat: A Systematic Review of the Persuasiveness of Front-of-Pack Cues on Food Packages for Children vs. Adults

“…People eat more when they are given multiple small packages, however, a phenomenon referred to as the partitioning paradox [82]. Several studies outside this review have suggested that the impact of cues such as package and portion size can (partially) be explained by normative influence, whereby people rely on these cues to make judgements about the appropriate consumption size [83,84]. However, no study in the review measured whether perceived norms function as a mediator of the package size effect.…”

Increasing the Proportion of Plant-Based Foods Available to Shift Social Consumption Norms and Food Choice among Non-Vegetarians

“…As far as we are aware, this is the first study to empirically examine different psychological responses towards an increased proportion of plant-based foods available in assortment structures [7,8]. We particularly showed that descriptive norms can be inferred from the number of plant-based foods available, providing further evidence for the proposition that social norms are embedded in physical aspects of food environments [17,19,25]. The proportion of plant-based (versus animal source) foods available may serve as a cue that implies a consumption norm reflecting what other people typically choose, rather than reflecting the appropriate choice according to others (i.e., an injunctive norm).…”

“…Consumers observing a relatively greater supply of plant-based foods may believe that these products are popular because of a high demand (i.e., greater consumption of these products by others) [7]. This explanation is related to a descriptive norm indicating what other people normally do in that environment [18]; it is supported by previous studies suggesting that descriptive norms can influence behavior through physical aspects in food environments without seeing others [17,[19][20][21]. Likewise, we argue that consumers may (also) infer that a greater availability of plant-based foods signals what other people consider as the appropriate choice in that environment.…”

“…The order of presentation of mediators was evenly randomized, as well as the order of presentation of burgers regarding each mediator; (b) the quality control question [27] (see Supplementary Materials (Methods: Study 1)); (c) the liking and familiarity items (see Supplementary Materials (Methods: Study 1)). The liking and familiarity items for each burger were presented on the same page, but the different burgers were presented on separate pages in an evenly randomized order; (d) the meat attachment items (items were presented per subscale); (e) the frequency of meat consumption item [28] (see Supplementary Materials (Methods: Study 1)); (f) the same mood questionnaire as in Stage 3 (to corroborate the cover story); (g) their awareness of the study aim question [19] (see Supplementary Materials (Methods: Study 1)); (h) their demographic information (age, sex, nationality, and education); (i) the question about any allergies or intolerances for the included burgers.…”

“…Likewise, we argue that consumers may (also) infer that a greater availability of plant-based foods signals what other people consider as the appropriate choice in that environment. This explanation is related to an injunctive norm indicating what other people approve of in that environment [18] and is built upon the idea that consumers interpret the number of products available as a deliberate decision by the food provider (e.g., supermarket) [19]. This normative interpretation of availability as a reflection of the choice that consumers are supposed to make according to others is consistent with previous research showing that consumers believe that a served portion size in a given situation is chosen after some deliberation, determining their food intake 24 h later [19].…”