Modern Diet and Physiology Research Center, New Haven, CT, USA.
Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
Nat Metab. 2023 Sep;5(9):1483-1493. doi: 10.1038/s42255-023-00874-z. Epub 2023 Aug 28.
It is well-known that food-cue reactivity (FCR) is positively associated with body mass index (BMI) and weight change, but the mechanisms underlying these relationships are incompletely understood. One prominent theory of craving posits that the elaboration of a desired substance through sensory imagery intensifies cravings, thereby promoting consumption. Olfaction is integral to food perception, yet the ability to imagine odours varies widely. Here we test in a basic observational study whether this large variation in olfactory imagery drives FCR strength to promote adiposity in 45 adults (23 male). We define odour-imagery ability as the extent to which imagining an odour interferes with the detection of a weak incongruent odour (the 'interference effect'). As predicted in our preregistration, the interference effect correlates with the neural decoding of imagined, but not real, odours. These perceptual and neural measures of odour imagery are in turn associated with FCR, defined by the rated craving intensity of liked foods and cue-potentiated intake. Finally, odour imagery exerts positive indirect effects on changes in BMI and body-fat percentage over one year via its influences on FCR. These findings establish odour imagery as a driver of FCR that in turn confers risk for weight gain.
众所周知，食物线索反应性（FCR）与体重指数（BMI）和体重变化呈正相关，但这些关系的潜在机制尚不完全清楚。一种流行的渴望理论假设，通过感官意象对渴望物质的详细描述会加剧渴望，从而促进消费。嗅觉是食物感知的重要组成部分，但想象气味的能力差异很大。在这里，我们在一项基础观察研究中测试了这种嗅觉意象的巨大差异是否会通过促进肥胖来增强 45 名成年人（23 名男性）的 FCR 强度。我们将气味想象能力定义为想象一种气味干扰微弱不和谐气味检测的程度（“干扰效应”）。正如我们预先注册中预测的那样，干扰效应与想象但不是真实气味的神经解码相关。这些嗅觉意象的感知和神经测量反过来又与 FCR 相关，FCR 通过对喜欢的食物的渴望强度和线索增强摄入进行定义。最后，气味意象通过其对 FCR 的影响，对一年中 BMI 和体脂百分比的变化产生积极的间接影响。这些发现确立了嗅觉意象是 FCR 的驱动因素，而 FCR 反过来又增加了体重增加的风险。
