There’s lots of lore surrounding MREs. One prominent myth is that the chewing gum contained in every MRE has laxative properties, presumably to counter that other myth that MREs induce constipation (a myth for another day!).
A friend of mine, another prior-service officer who did time in the 82nd actually emailed Natick, the folks who design the MREs and asked them about the gum myth. Here is their response:
Thank you for your comments and interest in the U.S. Army Natick Soldier
Research, Development and Engineering Center (NSRDEC), Department of Defense
(DoD), Combat Feeding Directorate (CFD). The Combat Feeding Program has an
active interest in receiving proposals and comments pertaining to new ideas,
suggestions, innovative concepts, and products that could be of benefit to
The MRE™ is part of the Continuous Product Improvement process under the
Fielded Individual Ration Improvement Project (FIRIP). Feedback from
Operation Desert Shield/Storm suggested that Warfighters would consume more
if their preferences were taken into consideration. In 1993, the FIRIP was
initiated to improve the variety, acceptability, consumption and nutritional
intake of individual combat rations to enhance performance on the
battlefield. Today, all components that are put into or taken out of an MRE™
must first be Warfighter Recommended, Warfighter Tested, Warfighter
Approved™. From 1993 through 2013, over 260 new items have been approved and
added to menus and over 65 of the least acceptable items have been removed.
Attached is Natick PAM 30-25 Operational Rations of the DoD
http://nsrdec.natick.army.mil/media/print/OP_Rations.pdf which highlights
the entire family of fielded rations. Pages 14-16 provides the detailed
information regarding MRE individual components that you inquired about. The MRE™ gum does not function as a laxative.
Another myth, solved.