title: Slave to habit? Obesity is associated with decreased behavioural sensitivity to reward devaluation.
abstract: The motivational value of food is lower during satiety compared to fasting. Dynamic changes in motivational value promote food seeking or meal cessation. In obesity this mechanism might be compromised since obese subjects ingest energy beyond homeostatic needs. Thus, lower adaptation of eating behaviour with respect to changes in motivational value might cause food overconsumption in obesity. To test this hypothesis, we implemented a selective satiation procedure to investigate the relationship between obesity and the size of the behavioural devaluation effect in humans. Lean to obese men (mean age 25.9, range 19-30 years; mean BMI 29.1, range 19.2-45.1 kg/m(2)) were trained on a free operant paradigm and learned to associate cues with the possibility to win different food rewards by pressing a button. After the initial training phase, one of the rewards was devalued by consumption. Response rates for and wanting of the different rewards were measured pre and post devaluation. Behavioural sensitivity to reward devaluation, measured as the magnitude of difference between pre and post responses, was regressed against BMI. Results indicate that (1) higher BMI compared to lower BMI in men led to an attenuated behavioural adjustment to reward devaluation, and (2) the decrease in motivational value was associated with the decrease in response rate between pre and post. Change in explicitly reported motivational value, however, was not affected by BMI. Thus, we conclude that high BMI in men is associated with lower behavioural adaptation with respect to changes in motivational value of food, possibly resulting in automatic overeating patterns that are hard to control in daily life.
authors.affiliation: Leipzig University Medical Center, IFB Adiposity Diseases, Philipp-Rosenthal-Straße 27, Leipzig, Germany; Department of Neurology, MPI for Human Cognitive and Brain Sciences, Stephanstraße 1A, Leipzig 04103, Germany; Leipzig University Medical Center, CRC 1052, Subprojects A1 & A5, Leipzig, Germany. Electronic address: horstmann@cbs.mpg.de.
authors.forename: Annette
authors.initials: A
authors.lastname: Horstmann
authors.affiliation: Department of Neurology, MPI for Human Cognitive and Brain Sciences, Stephanstraße 1A, Leipzig 04103, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Dietrich
authors.affiliation: Leipzig University Medical Center, IFB Adiposity Diseases, Philipp-Rosenthal-Straße 27, Leipzig, Germany; Department of Neurology, MPI for Human Cognitive and Brain Sciences, Stephanstraße 1A, Leipzig 04103, Germany.
authors.forename: David
authors.initials: D
authors.lastname: Mathar
authors.affiliation: Department of Neurology, MPI for Human Cognitive and Brain Sciences, Stephanstraße 1A, Leipzig 04103, Germany; Leipzig University Medical Center, CRC 1052, Subprojects A1 & A5, Leipzig, Germany.
authors.forename: Maria
authors.initials: M
authors.lastname: Pössel
authors.affiliation: Leipzig University Medical Center, IFB Adiposity Diseases, Philipp-Rosenthal-Straße 27, Leipzig, Germany; Department of Neurology, MPI for Human Cognitive and Brain Sciences, Stephanstraße 1A, Leipzig 04103, Germany; Leipzig University Medical Center, CRC 1052, Subprojects A1 & A5, Leipzig, Germany; Department of Cognitive Neurology, University Hospital Leipzig, Liebigstraße 16, Leipzig, Germany; Mind & Brain Institute, Berlin School of Mind and Brain, Humboldt-University, Unter den Linden 6, Berlin, Germany.
authors.forename: Arno
authors.initials: A
authors.lastname: Villringer
authors.affiliation: Leipzig University Medical Center, IFB Adiposity Diseases, Philipp-Rosenthal-Straße 27, Leipzig, Germany; Department of Neurology, MPI for Human Cognitive and Brain Sciences, Stephanstraße 1A, Leipzig 04103, Germany; Leipzig University Medical Center, CRC 1052, Subprojects A1 & A5, Leipzig, Germany.
authors.forename: Jane
authors.initials: J
authors.lastname: Neumann
mesh_terms: D000222:Adaptation, Physiological; D000328:Adult; D015992:Body Mass Index; D001835:Body Weight; D002149:Energy Intake; D005247:Feeding Behavior / Q000523:psychology*; D015438:Health Behavior; D006801:Humans; D006815:Hunger; D006963:Hyperphagia / Q000523:psychology; D016014:Linear Models; D008297:Male; D008954:Models, Biological; D009042:Motivation; D009765:Obesity / Q000523:psychology*; D012201:Reward; D012527:Satiation; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: Control of food intake; Devaluation; Goal-directed; Habitual; Obesity; Reward sensitivity