In AD&D, Create Food & Water is a 3rd level cleric spell. It provides food for three people per level of the caster. The 3rd level spells-per-day for a cleric maxes out at nine at 19th level. A 19th level cleric could support 513 people. Note also, however, that the casting time has increased to 10 minutes. (The Expert book doesn’t list a casting time, so I presume that it is 10 seconds—i.e. 1 combat round.)
In Labyrinth Lord (both the base game and the AEC), Create Food & Water is a 4th level cleric spell. It only provides for three people regardless of the level of caster. So, a 20th level LL cleric, with six 4th level spells per day, could only support 18 people.
Note that both here and for my earlier Expert D&D (1981) numbers, I’m treating the cleric’s spells-per-day limit as a strict daily limit. If the rules or DM allows for re-prep’ing spells within a day then even more people could be supported, but at the cost of a lot of the cleric’s time.
Lamentations of the Flame Princess Weird Fantasy Role-playing lacks such a spell.