Sinking or floating food

Watched a u tube video about feeding fish, they reckon that you should only few7ed sinking foods as floating foods cause the fish to gasp at the surface and injest air which affects their swim bladder . .Anyone heard anything about this . All my foods i feed are floating at least for a while and normally get eaten before they sink .

i think really depends on the fish and what they do in the wild. some fish pick at debrise and leaves and fruit floating at surface. i find with likes of guppies and probably killi they dont really eat food at bottom