1600 grams is around 3.5 lbs, which is on the heavy side. Still, if one can get at least one, maybe two days out of one ORP, that starts approaching 1 lbs/meal.

There is, however, one little drawback for those of us who dwell on the west side of "the pond." I've done several searches, but ORP's seem to be unavailable in the US. MRE's are ubiquitous, but nary an ORP is to be found.