i think a female's disinterest in consuming food, is triggered more by stress, than the actual act of holding. although young females tend to fast more readily than experienced ones, most keepers of colonizing species witness holding females grazing privately.
a poor choice of tank mates, might also prompt a female to tighten up her lips (common in crowded malawi type set ups), as will moving her away from the group into one of those terrifying 'quarantee tank' set ups. :roll: