Depends upon the age of the fish. Fry should be fed 3 or 4 times a day. Larger cichlids can be fed once a day. Skipping a day of feeding is also good for the larger fish. As far as the amount of aggression goes, feeding will have little effect. Lowering the temperature will reduce the aggression a bit.
Agree with Joe
but since you do not specify the species you have,
I would also note that algae grazers such as Tropheus and other vegetarians can be fed more often, but with small amounts, because in nature they spend most of their day constantly grazing aufwuchs.
Piscivores do not always catch prey on a daily basis, so can be fed less often.