I think over feeding probably goes for most aquarium fish, but maybe it shows on the slender body type of crenicichla more easily? It takes very little food to get my little lugubris pike a rounded belly, but I can stuff my herichthys carpintis full of food and it doesn't show at all.
Aqua Imports recently received a couple of "jumbo" lenticulata and they had obviously not eaten well in the recent past. They had sunken bellies and looked so markedly different from the stuffed sausage look of most large, captive lugubris pikes. I hope to keep my marmorata a bit more svelte as she matures.