1\) Abstract of the study A positive energy balance (greater intake than expenditure) can explain weight gain and, when protracted, leads to overweight and obesity. The major question addressed in this proposal is if the timing of activation of specific regions of the brain is predictive of excessive food intake. Functional near infra-red spectroscopy (fNIR), seldom used in human eating studies, provides data similar to functional magnetic resonance imaging (fMRI) but allows for measurement of brain activation during food consumption. The investigator's pilot fNIR data reveal that varying patterns of regional PFC activation are associated with "loss of control" over eating, and that only 60% of individuals respond to acute protein intake with a reduction in food intake. Using fNIR and an acute protein challenge, the investigator will assess the effect of family history of obesity in humans on the satiation response to protein and concomitant activation of the prefrontal cortex (PFC). It is hypothesized that activation of the human medial PFC before the lateral PFC will result in greater intake of palatable food in those subjects with a proneness to obesity, and that these subjects will be less sensitive to the satiety-inducing effects of a protein preload. These results should provide an innovative and useful method for assessing risk for developing obesity and usefulness of preventative interventions.
