Activation in brain energy regulation and reward centers by food cues varies with choice of visual stimulus.
OBJECTIVE
To develop a non-invasive method of studying brain mechanisms involved in energy homeostasis and appetite regulation in humans by using visual food cues that are relevant to individuals attempting weight loss.


METHODS
Functional magnetic resonance imaging (fMRI) was used to compare brain activation in regions of interest between groups of food photographs.


METHODS
Ten healthy, non-obese women who were not dieting for weight loss.


METHODS
Independent raters viewed food photographs and evaluated whether the foods depicted should be eaten by individuals attempting a calorically-restricted diet. Based on their responses, we categorized photographs into 'non-fattening' and 'fattening' food groups, the latter characterized by high-caloric content and usually also high-fat or high-sugar content. Blood oxygen level-dependent (BOLD) response was measured by fMRI while participants viewed photographs of 'fattening' food, 'non-fattening' food, and non-food objects.


RESULTS
Viewing photographs of fattening food compared with non-food objects resulted in significantly greater activation in the brainstem; hypothalamus; left amygdala; left dorsolateral prefrontal cortex; left orbitofrontal cortex; right insular cortex; bilateral striatum, including the nucleus accumbens, caudate nucleus, and putamen; bilateral thalamus; and occipital lobe. By comparison, only the occipital region had greater activation by non-fattening food than by object photographs. Combining responses to all food types resulted in attenuation of activation in the brainstem, hypothalamus, and striatum.


CONCLUSIONS
These findings suggest that, in non-obese women, neural circuits engaged in energy homeostasis and reward processing are selectively attuned to representations of high-calorie foods that are perceived as fattening. Studies to investigate hormonal action or manipulation of energy balance may benefit from fMRI protocols that contrast energy-rich food stimuli with non-food or low-calorie food stimuli.
Schur
E A
EA
Division of General Internal Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA. ellschur@u.washington.edu
Kleinhans
N M
NM
Goldberg
J
J
Buchwald
D
D
Schwartz
M W
MW
Maravilla
K
K
D000328:Adult; D001069:Appetite Regulation / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D002755:Choice Behavior / Q000502:physiology*; D003463:Cues; D005260:Female; D005502:Food; D005518:Food Preferences / Q000523:psychology*; D006801:Humans; D007031:Hypothalamus / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010775:Photic Stimulation / Q000379:methods; D010781:Photography; D012201:Reward; D055815:Young Adult