title: (Still) longing for food: insulin reactivity modulates response to food pictures.
abstract: Overweight and obesity pose serious challenges to public health and are promoted by our food-rich environment. We used functional magnetic resonance imaging (fMRI) to investigate reactivity to food cues after overnight fasting and following a standardized caloric intake (i.e., a 75 g oral glucose tolerance test, OGTT) in 26 participants (body mass index, BMI between 18.5 and 24.9 kg m(-2)). They viewed pictures of palatable food and low-level control stimuli in a block design and rated their current appetite after each block. Compared to control pictures, food pictures activated a large bilateral network typically involved in homeostatically and hedonically motivated food processing. Glucose ingestion was followed by decreased activation in the basal ganglia and paralimbic regions and increased activation in parietal and occipital regions. Plasma level increases in insulin correlated with cue-induced appetite at the neural and behavioral level. High insulin increases were associated with reduced activation in various bilateral regions including the fusiform gyrus, the superior temporal gyrus, the medial frontal gyrus, and the limbic system in the right hemisphere. In addition, they were accompanied by lower subjective appetite ratings following food pictures and modulated the neural response associated with it (e.g., in the fusiform gyrus). We conclude that individual insulin reactivity is critical to reduce food-cue responsivity after an initial energy intake and thereby may help to counteract overeating.
authors.affiliation: Department of Psychiatry and Psychotherapy, Technische Universität Dresden, Dresden, Germany; Neuroimaging Center, Department of Psychology, Technische Universität Dresden, Dresden, Germany.
authors.forename: Nils B
authors.initials: NB
authors.lastname: Kroemer
authors.forename: Lena
authors.initials: L
authors.lastname: Krebs
authors.forename: Andrea
authors.initials: A
authors.lastname: Kobiella
authors.forename: Oliver
authors.initials: O
authors.lastname: Grimm
authors.forename: Sabine
authors.initials: S
authors.lastname: Vollstädt-Klein
authors.forename: Uta
authors.initials: U
authors.lastname: Wolfensteller
authors.forename: Ricarda
authors.initials: R
authors.lastname: Kling
authors.forename: Martin
authors.initials: M
authors.lastname: Bidlingmaier
authors.forename: Ulrich S
authors.initials: US
authors.lastname: Zimmermann
authors.forename: Michael N
authors.initials: MN
authors.lastname: Smolka
mesh_terms: D000293:Adolescent; D000328:Adult; D059031:Anticipation, Psychological / Q000502:physiology; D001066:Appetite / Q000187:drug effects / Q000502:physiology*; D001786:Blood Glucose / Q000032:analysis; D015992:Body Mass Index; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000502:physiology*; D003463:Cues; D005215:Fasting / Q000523:psychology; D005247:Feeding Behavior / Q000502:physiology*; D005260:Female; D005502:Food; D006706:Homeostasis; D006801:Humans; D006815:Hunger / Q000502:physiology*; D007328:Insulin / Q000097:blood / Q000502:physiology*; D008032:Limbic System / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008954:Models, Biological; D008960:Models, Psychological; D009415:Nerve Net / Q000502:physiology*; D010775:Photic Stimulation; D057181:Pleasure / Q000502:physiology; D055815:Young Adult
chemical_list: D001786:Blood Glucose; D007328:Insulin