The Christchurch City Mission says some parents are turning to its foodbank for help, as they fail to make ends meet despite working fulltime.
The mission said the increase in demand for its food parcels meant its supplies were running low, as it prepares to launch its annual Brown Paper Bag Appeal on 2 July.
Christchurch City missioner Matthew Mark said about 50 families were looking for food parcels each day.
There had also been an increase in people in the Christchurch area - 1300 in the last 12 months - using the charity's alcohol and drug detox services.
Mr Mark said some families were having to make tough choices.
One of the causes was people's wages, which had not kept pace with the increase in general costs, he said.