Which foods and which cichlids?
Some are carnivores and need a high protein diet, similar to good quality tropical flakes, so they will do OK on the flakes.
Others naturally have a more vegetable based diet and should be fed a diet with more vege or algae in the formula.
I feed my Kribensis normal flake food and they do fine. My Oscar gets cichlid pellets and and a mix of fresh food like raw fish and earthworms. But he's just a big greedy guts that can't be bothered with puny flakes of food.
MChorse13 is correct that many pellet food have the same basic ingredients as flakes, they are just a different shape. Flakes go soft quick and a easier for small fish to eat, pellets are more chunky and fill up large fish faster, but the ingredients may be basically the same.
Ian