Does eating nonsalty food with MSG make you thirsty?
MSG (monosodium glutamate) can trigger thirst simply because it's a spice or because foods with MSG often contain other spices.

Relationships between human thirst, hunger, drinking, and feeding (PubMed, 2008)


  Drinking may occur at meal times to facilitate chewing and swallowing,
  improve sensory stimulation and food palatability, reduce aversive
  sensations evoked by irritants such as spices, or in anticipation of
  physiological deprivation.


Thirst after ingestion large amounts of MSG is described here as part of Chinese restaurant syndrome; the mechanism involved is a transient release of acetylcholine:


  symptoms experienced by individuals following intravenous MSG were
  similar to those experienced by individuals following intravenous
  acetylcholine (ACH).


So, does MSG trigger thirst? It may, but not necessary.