Per the other thread on this -
http://www.project1999.org/forums/sh...7846#post37846 - it looks like this is a legit bug.
A "snack" sized food lasts as long as a "miraculous meal" sized food.
I made up a serving up fish rolls (0.1 weight, banquet meal sized food) and found they were being eaten at the same rate as a normal water flask.