"feeding" implies that you are doing it intentionally. its the act of becoming food for the enemy team.
if you are dying a lot because you went on tilt or had a bad game or your opponent completely sees through your every move and is always a step ahead, killing you in the process, that's not feeding.
Even if you go 2/15 like someone earlier mentioned.
only the feeding where you stop trying, walk up to the enemy to be slaughtered without defending yourself, walking into towers, dying to creeps on purpose, playing touch-down in their base, that feeding is intentional, toxic and therefore reportable.