Schools are digging into their teaching budgets, in some cases relying on donations from principals and teachers to feed children who turn up hungry.

A nationwide survey of lower decile school principals has indicated how many kids don't have breakfast or lunch, with those in some areas reporting up to 80 percent of students arriving without food each week.

Most of the 270 schools who responded to the New Zealand Principals' Federation questionnaire said they fed some of their students, with more than half feeding at least 20 per cent each week.

Principals reported using up to $5000 of their operations grants on feeding children each term and many also paid teacher aides to co-ordinate available programmes or help at breakfast and lunchtime.

The Principals' Federation which carried out the survey says in some cases teachers and principals are digging into their own pockets to feed pupils.

Among the respondents were 70 decile four and five schools, suggesting child poverty is creeping into middle income families.