title: To eat or not to eat: Effects of food availability on reward system activity during food picture viewing.
abstract: Neuroimaging studies have started to explore the role of food characteristics (e.g., calorie-content) and psychological factors (e.g., restrained eating, craving) for the human appetitive system, motivated by the significant health implications of food-choice, overeating and overweight/obesity. However, one key aspect of modern food environments, food availability, especially of high energy foods, has not been adequately modeled in experimental research. Food that is immediately available for consumption could elicit stronger reward system activity and associated cognitive control than food that is not currently available for consumption and this could vary as a function of energy density. To examine this question, 32 healthy participants (16 women) underwent functional magnetic resonance imaging while passively viewing available foods - i.e. foods that could be eaten during and after the experiment - and unavailable foods of either high or low-caloric density in a 2 × 2 design. Available compared to unavailable foods elicited higher palatability ratings as well as stronger neural activation in the orbitofrontal cortex (OFC), amygdala, and left caudate nucleus as well as in the anterior cingulate cortex (ACC) - and thus structures implicated in reward and appetitive motivation as well as cognitive control, respectively. Availability effects in the caudate were mainly attributable to the high calorie condition (availability × calorie density interaction). These neuroimaging results support the contention that foods are particularly rewarding when immediately available and particularly so when high in caloric density. Thus, our results are consistent with health promoting interventions utilizing a nudging approach, i.e. aiming at decreasing accessibility of high calorie and increasing accessibility of low calorie foods in daily life. Results also imply that controlling/manipulating food availability may be an important methodological aspect in neuroscientific eating research.
authors.affiliation: Centre for Cognitive Neuroscience, University of Salzburg, Austria; Department of Psychology, University of Salzburg, Austria. Electronic address: jens.blechert@sbg.ac.at.
authors.forename: Jens
authors.initials: J
authors.lastname: Blechert
authors.affiliation: Department of Psychology, Division of Social Psychology, University of Salzburg, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Klackl
authors.affiliation: Department of Psychology, Division of Clinical Psychology, Psychotherapy, and Health Psychology, Austria.
authors.forename: Stephan F
authors.initials: SF
authors.lastname: Miedl
authors.affiliation: Department of Psychology, Division of Clinical Psychology, Psychotherapy, and Health Psychology, Austria.
authors.forename: Frank H
authors.initials: FH
authors.lastname: Wilhelm
mesh_terms: D000679:Amygdala / Q000502:physiology; D015992:Body Mass Index; D002755:Choice Behavior; D003071:Cognition; D066249:Craving; D004435:Eating / Q000523:psychology*; D002149:Energy Intake; D005247:Feeding Behavior / Q000523:psychology; D005260:Female; D005518:Food Preferences / Q000523:psychology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009042:Motivation; D009765:Obesity / Q000517:prevention & control / Q000523:psychology; D017397:Prefrontal Cortex / Q000502:physiology; D011594:Psychometrics; D012201:Reward; D011795:Surveys and Questionnaires; D013649:Taste; D055815:Young Adult
keywords: Appetite; Availability; Eating behavior; Food picture viewing; High calorie; Hunger; Low caloric; Nudging; Orbitofrontal cortex; Restraint eating; Reward system; Striatum; fMRI