Reward circuitry responsivity to food predicts future increases in body mass: moderating effects of DRD2 and DRD4.
OBJECTIVE
To determine whether responsivity of reward circuitry to food predicts future increases in body mass and whether polymorphisms in DRD2 and DRD4 moderate these relations.


METHODS
The functional magnetic resonance imaging (fMRI) paradigm investigated blood oxygen level dependent activation in response to imagined intake of palatable foods, unpalatable foods, and glasses of water shown in pictures. DNA was extracted from saliva samples using standard salting-out and solvent precipitation methods.


METHODS
Forty-four adolescent female high school students ranging from lean to obese.


RESULTS
Future increases in body mass index (BMI).


RESULTS
Weaker activation of the frontal operculum, lateral orbitofrontal cortex, and striatum in response to imagined intake of palatable foods, versus imagined intake of unpalatable foods or water, predicted future increases in body mass for those with the DRD2 TaqIA A1 allele or the DRD4-7R allele. Data also suggest that for those lacking these alleles, greater responsivity of these food reward regions predicted future increases in body mass.


CONCLUSIONS
This novel prospective fMRI study indicates that responsivity of reward circuitry to food increases risk for future weight gain, but that genes that impact dopamine signaling capacity moderate the predictive effects, suggesting two qualitatively distinct pathways to unhealthy weight gain based on genetic risk.
Stice
Eric
E
Oregon Research Institute, 1715 Franklin Blvd., Eugene, OR 97403, USA. estice@ori.org
Yokum
Sonja
S
Bohon
Cara
C
Marti
Nate
N
Smolen
Andrew
A
D000293:Adolescent; D015992:Body Mass Index; D001921:Brain / Q000098:blood supply / Q000502:physiology*; D004326:Drinking / Q000502:physiology; D004435:Eating / Q000502:physiology*; D005260:Female; D005502:Food; D006801:Humans; D007092:Imagination / Q000502:physiology*; D008279:Magnetic Resonance Imaging; D009434:Neural Pathways / Q000098:blood supply / Q000502:physiology; D009765:Obesity / Q000175:diagnosis / Q000235:genetics / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D011110:Polymorphism, Genetic; D011446:Prospective Studies; D050637:Receptors, Dopamine D3 / Q000235:genetics* / Q000378:metabolism; D050638:Receptors, Dopamine D4 / Q000235:genetics* / Q000378:metabolism; D012201:Reward; D012463:Saliva / Q000737:chemistry / Q000378:metabolism; D014867:Water; D015430:Weight Gain / Q000235:genetics* / Q000502:physiology*
C493599:DRD4 protein, human; D050637:Receptors, Dopamine D3; D014867:Water; D050638:Receptors, Dopamine D4; D010100:Oxygen