Food as a percentage of body weight?

[Foo Hong]

It is said that fishes only require a certain small percentage in relation to their body weight for food amount.....somewhere in the region of no more than 5 percent. Can someone confirm?

[Myron Tay]

Any contributions on this?

[David Esguerra]

I have no real contribution but I would be in doubt of that, or else food fish won't be fed ad libitum in commercial farms.