The Reading Challenge, in its third year, has distributed 400,000 pizza wheels which meant children around the country have read 2,800,000 books.
This year, about 200,000 pizza wheels have been distributed across schools and libraries this year and the response had been "overwhelming", Mr Cumming said.
The response continues to be overwhelmingly positive and we are printing a further 50,000 Pizza Wheels this year to meet demand,"
"Prising kids' eyeballs away from screens and refocusing them on books is getting more and more difficult - but this initiative really appears to be connecting young minds to the benefits books can bring, both in terms of literacy and creativity."
Christchurch dietitian Lea Stening said providing free pizza to encourage children to read was a positive initiative.
"It's a treat food and occasionally pizza can be healthy. It doesn't have to be ladened with cheese.
However she said it depended on what children ate and drank with it.
"As long as they are supervised by a parent and not accompanied by chips and fizzy drink, I don't think there is a problem."
It also depended on the child's size and how active they were.
"If a child has three pieces, it's not a problem but it depends on the size of the child and the size of the pizza."
Stening encouraged children to eat thin-based pizza with more vegetables.
"I would aim to eat more chicken or seafood pizza and less ham and bacon."
Children participating in the challenge can choose one topping in their pizza including chicken, bacon, salami, tomato or onion.
The Hell Reading Challenge runs until December 4 this year.