Legget Kristina T, Cornier Marc-Andre, Rojas Donald C, Lawful Benjamin, Tregellas Jason R
Department of Psychiatry and
Division of Endocrinology, Metabolism and Diabetes, Department of Medicine, University of Colorado School of Medicine, Anschutz Medical Campus, Aurora, CO; Anschutz Health and Wellness Center, University of Colorado, Anschutz Medical Campus, Aurora, CO;
Am J Clin Nutr. 2015 Aug;102(2):249-55. doi: 10.3945/ajcn.115.106955. Epub 2015 Jun 24.
In our increasingly obesogenic environment, in which high-calorie convenience foods are readily available, food choices can drastically affect weight and overall health. Learned food preferences, which are developed through repeated pairings with positively and negatively valenced stimuli, can contribute to obesity susceptibility if positive attitudes toward high-calorie foods are developed. Thus, the modification of automatic associations with food may be a viable strategy to promote healthier eating behaviors.
In this study, we investigated the ability of an implicit priming (IP) intervention to alter responses to visual food cues by using an evaluative conditioning approach. The main objective was to implicitly (i.e., below conscious perception) associate disgust with high-calorie foods with the aim of reducing liking of these foods.
Participants were randomly assigned to active or control IP. In active IP (n = 22), high-calorie food images were implicitly primed with negatively valenced images, and low-calorie food images were implicitly primed with positively valenced images. In control IP (n = 20), all food images were primed with neutral images of fixation crosses. Food images were rated on the desire to eat immediately before and after IP.
A significant main effect of calorie (high compared with low; P < 0.001) and a significant calorie-by-group (active compared with control) interaction (P = 0.025) were observed. Post hoc tests identified a significantly greater high-calorie rating decline after active IP than after control IP (P = 0.036). Furthermore, there was significantly greater change in high-calorie ratings than in low-calorie ratings in the active group (P = 0.001). Active IP effects extended to high-calorie foods not specifically included in the intervention, which suggested an effect generalization. Moreover, a greater change in high-calorie ratings than in low-calorie ratings persisted 3-5 d after active IP (P < 0.007), which suggested lasting effects.
This study provides initial evidence that IP can be used to alter high-calorie food preferences, which could promote healthier eating habits.
在我们这个高热量方便食品随处可得的致胖环境日益严重的情况下，食物选择会极大地影响体重和整体健康。通过与正负价刺激反复配对形成的习得性食物偏好，如果对高热量食物形成了积极态度，就可能导致肥胖易感性增加。因此，改变对食物的自动联想可能是促进更健康饮食行为的一种可行策略。
在本研究中，我们采用评价性条件反射方法，研究内隐启动（IP）干预改变对视觉食物线索反应的能力。主要目的是在内隐层面（即低于意识感知）将厌恶与高热量食物联系起来，以减少对这些食物的喜爱。
参与者被随机分配到主动IP组或对照IP组。在主动IP组（n = 22）中，高热量食物图像与负价图像进行内隐启动，低热量食物图像与正价图像进行内隐启动。在对照IP组（n = 20）中，所有食物图像都与注视十字的中性图像进行启动。在IP前后，参与者对食物图像的进食欲望进行评分。
观察到热量的显著主效应（高热量与低热量相比；P < 0.001）以及热量与组别的显著交互作用（主动组与对照组相比；P = 0.025）。事后检验发现，主动IP后高热量评分的下降幅度显著大于对照IP后（P = 0.036）。此外，主动组中高热量评分的变化显著大于低热量评分的变化（P = 0.001）。主动IP效应扩展到未专门纳入干预的高热量食物，这表明存在效应泛化。此外，主动IP后3 - 5天，高热量评分的变化仍显著大于低热量评分的变化（P < 0.007），这表明存在持久效应。
本研究提供了初步证据，表明IP可用于改变高热量食物偏好，这可能促进更健康的饮食习惯。
