However, "if the child is not fed ... we know they don't learn.
"In the end they are a victim, they may well be a 6- or 7-year-old victim that can't stand up for themselves so we have some responsibility to do something about that."
The fastest way to tackle poverty remained through work and education and he told party members that controversial welfare reforms, led by Social Development Minister Paula Bennett, "may well prove to be one of the great legacies of this Government".
Staking out the ground for next year's election, Mr Key said it would be "quite a different election to what you normally see".
"Normally elections are fought between the centre-left and the centre-right. That is not what's going to take place next year. David Shearer has cut his cloth and it is wrapped around Russel Norman.
"But that now becomes an election between the centre-right and the far-left."
Mr Key yesterday would not rule out working with New Zealand First, depending on the outcome of the election, in spite of its leader Winston Peters' latest tirade against Asian immigrants.
"We'll make a decision in 2014."