Students are missing the equivalent of a term of school by not eating breakfast, a new report says.

The Foodbank data shows students lose two hours of learning a day due to a lack of concentration and behaviour problems if they miss breakfast.

Foodbank spokeswoman Nicci Skerl said the report surveyed 532 teachers across Australia and 67 per cent confirmed some students were turning up to school hungry.

"We knew the numbers were increasing," she said.

"They've found, stats-wise, they are actually losing a whole term in tiredness, lethargy, lack of concentration."

The organisation distributes surplus food to the welfare sector and helps schools deliver free breakfast programs.

YMCA Vocational School in Logan, south of Brisbane, offers toast, fruit and cereal to students five days a week.

Teacher Jilly Moore said the vast majority of students would not have eaten breakfast when they arrived at school.

"The majority of our kids have come from fairly traumatic backgrounds, so have experienced trauma in their lifetime," Ms Moore said.

"This is fairly low social-economic area so high amount of disadvantage and at-risk youth."

Ms Moore said she had noticed an improvement in learning since the breakfast program was introduced.

"It makes a massive difference in the classroom, particularly we are finding in the first class of the day they are a lot more settled," she said.

"We've definitely noticed a big increase in concentration levels and behaviour as well - positive behaviours."

Foodbank said many families in Australia were doing it tough at the moment.

Ms Skerl said the food bill was often one of the first things parents would cut back on.

"It's not just unemployment or homelessness, it's underemployment. so that's when families have only been able to get six hours a week, that is not going to pay the bills," she said.

The survey also found 82 per cent of teachers reported an increased workload due to hungry students.