The NMB variant impacts the levels of a peptide from the gastrointestinal tract, which inhibits food intake through the influence of eating behaviours. Some of it’s biological roles are within the serotonergic system, stimulation of the pancreatic appetite hormone peptide YY (PYY) and regulating output from the pituitary. One eating behaviour it is associated to is disinhibition – the tendency to overeat in response to external or internal cues (e.g. emotions).
Source: 1000 Genome Project. Global averages for both sexes