I would assume you are powering these receptacles via a local generator...if so you should be covered even if the NEC doesn't apply directly to the food truck itself. Just FOOD for thought and again assuming you have a generator in the equation. (2017 NEC Mind You)
445.20 Ground-Fault Circuit-Interrupter Protection for Receptacles
on 15-kW or Smaller Portable Generators.
Receptacle outlets that are a part of a 15-kW or smaller portable generator
shall have listed ground-fault circuit-interrupter protection
(GFCI) for personnel integral to the generator or receptacle as
indicated in either (A) or (B):
(A) Unbonded (Floating Neutral) Generators. Unbonded
generators with both 125-volt and 125/250-volt receptacle
outlets shall have listed GFCI protection for personnel integral
to the generator or receptacle on all 125-volt, 15- and
20-ampere receptacle outlets.
Exception: GFCI protection shall not be required where the 125-volt
receptacle outlets(s) is interlocked such that it is not available for use
when any 125/250-volt receptacle(s) is in use.
(B) Bonded Neutral Generators. Bonded generators shall be
provided with GFCI protection on all 125-volt, 15- and
20-ampere receptacle outlets.
Informational Note: Refer to 590.6(A)(3) for GFCI requirements
for 15-kW or smaller portable generators used for temporary
electric power and lighting.
Exception to (A) and (B): If the generator was manufactured or remanufactured
prior to January 1, 2015, listed cord sets or devices incorporating
listed GFCI protection for personnel identified for portable use
shall be permitted.
AGAIN....no comments that Food trucks do not need to meet the NEC....Yeah we have established that. I am just an outside of the BOX thinker!