Versluis Iris, Papies Esther K, Marchiori David
Department of Econometrics, Erasmus School of Economics, Burgemeester Oudlaan 50, NL-3062 PA Rotterdam, The Netherlands.
Department of Social and Organizational Psychology, Utrecht University, Heidelberglaan 1, NL-3584 CS Utrecht, The Netherlands.
Appetite. 2015 Apr;87:116-26. doi: 10.1016/j.appet.2014.12.097. Epub 2014 Dec 17.
People eat more from large than from small packs, which is known as the pack size effect. We hypothesized that providing a serving size recommendation would reduce the influence of the pack size on consumption and would thus diminish the pack size effect. Moreover, we hypothesized that a pictorial serving size recommendation, displaying food amounts visually, would be more effective than a non-pictorial recommendation that communicates the recommended amount in grams only. We tested these hypotheses in two online experiments (N = 317 and N = 324) and in one lab experiment (N = 89). In the online experiments, participants were shown a small or a large pack of unhealthy snacks, with or without a serving size recommendation. The main outcome measure was expected consumption. Replicating the pack size effect in an online setting, we found that participants expected to consume more food from large than from small packs. Furthermore, the pack size effect was considerably stronger for men than for women. Importantly, when including portion size preferences as a covariate, the pictorial serving size recommendation significantly reduced expected consumption, especially when placed on a large pack, as hypothesized. The non-pictorial serving size recommendation had no effect. In the lab experiment, students received a large bag of M&M's which did or did not contain the pictorial serving size recommendation. We again included general portion size preferences as a covariate. The serving size recommendation significantly lowered the amount of M&M's that participants served themselves, but only when participants reported to have noticed the serving size recommendation. We conclude that providing a pictorial serving size recommendation can be an effective intervention strategy to reduce the pack size effect, if it attracts sufficient attention.
人们从大包装中摄取的食物比从小包装中摄取的更多，这被称为包装尺寸效应。我们假设提供一份食用量建议会减少包装尺寸对食物摄入量的影响，从而减弱包装尺寸效应。此外，我们还假设，以图片形式展示食物量的食用量建议，会比仅以克数形式传达建议量的非图片形式的建议更有效。我们在两项在线实验（N = 317和N = 324）以及一项实验室实验（N = 89）中对这些假设进行了测试。在在线实验中，向参与者展示一小包或一大包不健康零食，有无食用量建议。主要的结果指标是预期摄入量。我们在在线环境中重现了包装尺寸效应，发现参与者预期从大包装中摄取的食物比从小包装中摄取的更多。此外，男性的包装尺寸效应比女性强得多。重要的是，当将份量偏好作为协变量纳入分析时，如我们所假设的，图片形式的食用量建议显著降低了预期摄入量，尤其是当它放在大包装上时。非图片形式的食用量建议则没有效果。在实验室实验中，学生们收到一大袋M&M's巧克力豆，其中有的包含图片形式的食用量建议，有的则没有。我们再次将一般份量偏好作为协变量纳入分析。食用量建议显著降低了参与者自取的M&M's巧克力豆的数量，但前提是参与者报告说注意到了食用量建议。我们得出结论，如果能吸引足够的注意力，提供图片形式的食用量建议可以成为减少包装尺寸效应的有效干预策略。
