fMRI links defective brainwiring, high risk of obesity

Women with a weakened brain "reward circuitry" are at increased risk of weight gain over time and potential obesity, according to two studies from researchers at the University of Oregon. The risk increases for women who also have a gene associated with compromised dopamine signaling in the brain.

Lead author Eric Stice, Ph.D., and colleagues at the university's Lewis Center for Neuroimaging prospectively enrolled 43 young adult women and 33 adolescent girls with respective mean body mass indexes of 28.6 and 24.3. Subjects underwent 12- month BMI tracking plus testing for Taq1A1 allele, a genetic variation linked to dopamine D2 reduction.

The investigators found subjects with abnormal striatal activation after downing milkshakes and those with the A1 allele were more likely to gain weight over time. Findings appeared in the Oct. 17 issue of Science.