Student advocate Tania Cumming and student support centre administrator Jessica Myers said 173 students had used the foodbank so far this year, up from 40 in the corresponding period last year.
Each student is given a food parcel designed to meet nutritional requirements for up to seven days.
Ms Myers said students were struggling to find part-time or casual jobs and were increasingly finding their student loan or allowance did not cover living costs.
Staff at the centre had also seen a "noticeable number" of students with high power bills, many of more than $1000, leaving them unable to buy food.
Because of the high demand, the foodbank has already exceeded the normal budget which is set according to the previous year's demand.
Funding comes from the OUSA budget, to which students make a contribution as part of their fees.
The foodbank has had only two donations this year.
"We do not currently receive any external funding and we do not receive as many donations as we would like," Ms Myers said.
This might be because many people were unaware there was a foodbank, she said.
Presbyterian Support chief executive Gillian Bremner said more students were using its services.
About 4500 people use the Presbyterian Support foodbank each year.
In the 2006-07 financial year 12% (540) were students; in the year to the end of June that number rose to 16% (720).
Mrs Bremner agreed many students were unable to find part-time or casual work and this made it a struggle for them to get by.
Students, like other clients, were offered budgeting help and before a foodbank parcel was handed, out they were asked what other services they had used.
Ms Myers said only OUSA members with Student ID could access the foodbank, and each student could be helped only twice a semester.
Students were not judged on what they spent money on, she said.
"Regardless of what has led to the student's current situation, we will still provide the student with food if they need it.
"We do also offer budgeting advice and other support services so that we can help students to prevent similar situations arising in the future.
We have no reason to believe our service is being abused."
Students were given information about other support services such as the university's student assistance fund and the special needs grant from Studylink.
• Donations can be made at the OUSA student support centre at 5 Ethel Benjamin Pl, open 9am-4.30pm, Monday to Friday.
