It may be that
the sensory experience of MSG acts to prepare for protein ingestion
and so contributes to the enhanced satiating effects of protein. Thus paradoxicallyMSG
could theoretically enhance appetite, through its effects
on flavour, and at the same time enhance satiety by allowing the body
to prepare for ingestion of protein. If so, then MSG may lead to reduced
satiation (as a consequence of its effects on palatability) but enhanced
satiety, by acting as a cue for protein ingestion. Although one study
[38] found no differences in satiety between protein preloads varying
in MSG, there is evidence that gut glutamate sensing mechanisms
enhance satiety in animals [39] and MSG has been related to gastric
increases in GLP-1 secretion 30 min after a test meal when compared
with sodium chloride