In search of the most reproducible neural vulnerability factors that predict future weight gain: analyses of data from six prospective studies

We tested if we could replicate the main effect relations of elevated striatum and lateral orbitofrontal cortex (OFC) response to high-calorie food stimuli to weight gain reported in past papers in six prospective datasets that used similar functional MRI (fMRI) paradigms. Participants in Study 1 (N = 37; M (mean) age = 15.5), Study 2 (N = 160; M age = 15.3), Study 3 (N = 130; M age = 15.0), Study 4 (N = 175; M age = 14.3), Study 5 (N = 45; M age = 20.8) and Study 6 (N = 49; M age = 31.1) completed fMRI scans at the baseline and had their body mass index (BMI) and body fat (Studies 4 and 6 only) measured at the baseline and over follow-ups. Elevated striatal response to palatable food images predicted BMI gain in Studies 1 and 6 and body fat gain in Study 6. Lateral OFC activation did not predict weight gain in any of the six studies. The result provide limited support for the hypothesis that elevated reward region responsivity to palatable food images predicts weight gain. Factors that make replication difficult are discussed and potential solutions considered.