Thomas Jason M, Liu Jinyu, Robinson Eric L, Aveyard Paul, Herman C Peter, Higgs Suzanne
School of Psychology, University of Birmingham Birmingham, UK.
Department of Psychological Sciences, University of Liverpool Liverpool, UK.
Front Psychol. 2016 Mar 30;7:442. doi: 10.3389/fpsyg.2016.00442. eCollection 2016.
There is evidence that social norm messages can be used to promote the selection of fruit and vegetables in low habitual consumers of these foods but it is unclear whether this effect is sustained over time. It is also unclear whether information about others' liking for a food (liking norm) could have the same effect. Using a 2 × 5 × 2 experimental design we investigated the effects of exposure to various messages on later intake from a food buffet and whether any effects were sustained 24 h after exposure in both low and high consumers of vegetables. There were three factors: delay (immediate food selection vs. food selection 24 h after exposure), message type (liking norm, descriptive norm, health message, vegetable variety condition, and neutral control message), and habitual consumption (low vs. high). The buffet consisted of three raw vegetables, three energy-dense foods, and two dips. For vegetables and non-vegetables there were no main effects of message type, nor any main effect of delay. There was a significant message × habitual vegetable consumption interaction for vegetable consumption; however, follow up tests did not yield any significant effects. Examining each food individually, there were no main effects of message type, nor any main effect of delay, for any of the foods; however, there was a message × habitual vegetable consumption interaction for broccoli. Consumption of broccoli in the health message and descriptive norm conditions did not differ from the control neutral condition. However, habitually low consumers of vegetables increased their consumption of broccoli in the vegetable variety and liking norm conditions relative to habitual low vegetable consumers in the neutral control condition (p < 0.05). Further, investigation of the effects of the liking norm and vegetable variety condition on vegetable intake is warranted. This trial is listed as NCT02618174 at clinicaltrials.gov.
有证据表明,社会规范信息可用于促进这些食物的低习惯消费者选择水果和蔬菜,但尚不清楚这种效果是否能长期持续。同样不清楚的是,关于他人对某种食物的喜好信息(喜好规范)是否会产生相同的效果。我们采用2×5×2实验设计,研究了接触各种信息对之后从食物自助餐中摄入量的影响,以及在蔬菜低消费者和高消费者中,接触信息24小时后是否仍有任何影响。有三个因素:延迟(立即选择食物与接触信息24小时后选择食物)、信息类型(喜好规范、描述性规范、健康信息、蔬菜种类条件和中性对照信息)以及习惯消费(低与高)。自助餐包括三种生蔬菜、三种高能量食物和两种蘸酱。对于蔬菜和非蔬菜,信息类型没有主效应,延迟也没有主效应。对于蔬菜消费,信息×习惯蔬菜消费存在显著交互作用;然而,后续测试未产生任何显著影响。单独检查每种食物,信息类型没有主效应,延迟也没有主效应;然而,西兰花存在信息×习惯蔬菜消费交互作用。在健康信息和描述性规范条件下西兰花的消费量与对照中性条件下没有差异。然而,相对于中性对照条件下的习惯低蔬菜消费者,习惯低蔬菜消费者在蔬菜种类和喜好规范条件下增加了西兰花的消费量(p<0.05)。此外,有必要进一步研究喜好规范和蔬菜种类条件对蔬菜摄入量的影响。该试验在clinicaltrials.gov上登记为NCT02618174。