On a very simple level, your weight depends on the number of calories you consume, how many of those calories you store, and how many you burn up. Looking at the first factor, since 1970, the size of individual food portion sold in supermarkets has grown 10-fold (Wansink & Van Ittersum, 2007). This growth of portion sizes has played an important role in the development of overweight and obesity. Indeed, consumers consider those individual food portions as consumption norms (Birch, Engell, & Rolls, 2000; Birch, McPhee, Shoba, Steinberg, & Krehbiel, 1987; Versluis & Papies, 2016). For this reason, consumers automatically eat more from larger food portions than smaller food portions, that is called “the portion size effect” (Rolls, Morris, & Roe, 2002; Wansink et al., 2005; Zlatevska, Dubelaar, & Holden, 2014).
Through two studies, we examined whether the action of mentally simulating the experience of eating the portion of food might reduce this portion size effect. Mental simulation can potentially reactivate some of the brain areas that are recruited during consumption, and produce similar sensations (Barsalou, 2008; Chen, Papies, & Barsalou, 2016; Simmons, Martin, & Barsalou, 2005). Thus, the mental simulation of eating a large quantity of food may affect satiety and give rise to feelings of fullness (Larson et al., 2014; Toepel et al., 2015), that might reduce the portion size effect. Moreover, simulate pleasant scenarios of eating food products has been shown to increase the purchase intent, and the willingness to pay for smaller food portions (Elder & Krishna, 2012; Cornil & Chandon, 2016), that can be interesting for food marketers.
In Study 1, we looked at the spontaneous simulation of eating experiences of consumers, when pictures of different (medium, large, very large) portions of French fries were displayed. The results of Study 1 revealed that people simulating more eating experiences found the food to be more appetizing, and expressed greater purchase intentions than those simulating less eating experiences. Furthermore, contrary to those latter, people simulating more eating experiences selected a smaller percent of food in the very large portion than in the medium food portion. However, the amount of food selected in this very large portion was more important than in the medium portion, thus suggesting that spontaneous simulation of eating experiences reduce the portion size effect, but does not eliminate it entirely.
In Study 2, participants were explicitly asked to imagine the sensory experience of eating, when pictures of different (smaller, larger) portions of chocolate bars were displayed. The results of Study 2 indicate that the portion size effect can be reduced significantly by directly asking consumers to imagine the sensory experience of eating the entire portion of food. Contrary to consumers that did not imagine the eating experience, they did not select significantly more squares in the larger chocolate bar than in the smaller chocolate bar. Interestingly, those participants that imagined the eating experience evaluated the smaller chocolate bar as more appetizing and more calorific. This result may indicate that imagining the sensory experience of eating not only increases the expected pleasure of smaller food portions, but might also increase expected satiety that enhances the rewarding value of the smaller food portion (Brunstrom & Shakeshaft, 2009).
The two studies reported here have implications both for public policy and for the food industry. By promoting sensory experience of eating food portions, public policy would help to reduce the portion size effect, and thus overconsumption (Petit, Basso, et al., 2016, Petit, Merunka, et al., 2016). Food marketers could also follow this strategy, that has been shown to increase the willingness to pay for smaller food portions, and thus reduce their economic costs (Cornil & Chandon, 2016).