Around one in six GPs have been asked to refer patients to a food bank in the past year, a snapshot poll suggests.
The survey of 522 family doctors for GP magazine Pulse found 16% had been asked to refer patients.
It comes after Pulse reported concerns among GP leaders that practices are being put in an "impossible position" by charities that require a referral before they will offer help.
Such referrals are aimed at making sure support reaches the most needy and can come from places such as schools, GPs and job centres.
Senior GPs have said the system can put a strain on the doctor-patient relationship, as well as taking up appointments.
Last year, Pulse also reported a 21% increase in requests for GPs to verify work capability due to cuts to the welfare system.
Professor Clare Gerada, former chair of the Royal College of GPs, said GPs were being caught up in the "hoops" the genuinely needy had to jump through to get help.
She said: "Poverty is an enormous workload issue and, again, it's the inverse care rule because it creates more work for GPs in poorer areas who don't get resourced for it so you end up with more work and less time.
"People do naturally turn to their GPs, they don't know where else to go, so they come to you. And because we get so much criticism, I get so fed-up.
"We're there trying to sort out everybody's problems and meanwhile the posh middle classes are complaining because they can't get access to us."
Pulse editor Steve Nowottny said: ''That a significant number of patients are now going to their GP asking to be referred to a food bank is clearly a concern - both because of the extent of need it suggests among patients, but also because of the knock-on impact on general practice, which is already stretched very thin.
"GPs often feel as though they are asked to do everything, and increasingly that includes acting as a support agency for patients who may be struggling as a result of the recession.
"Every GP is committed to doing whatever they can to help their patients - but with finite resources, this kind of work inevitably diverts GPs from the rest of their job and leaves them less time to spend with other patients."
Chris Mould, chairman of the Trussell Trust network of food banks, said: " GPs should have the ability to refer to a food bank when they come across a patient who they believe needs a food bank for health reasons, especially as levels of malnutrition are reported to be increasing.
"Some GPs are contacting food banks to ask them to help people visiting their surgeries who are suffering various sicknesses caused by not eating.
"GPs should not, however, be placed in a position to assess whether someone needs a food bank when the crisis is not health-related and they do not have enough information to make an accurate assessment of a patient's situation.
"Food banks work hard to partner with a whole range of relevant professionals in the community who can refer people to food banks.
"If a doctor is asked to refer a patient to a food bank for a reason that is not health-related, such as debt, it is better for the GP to suggest that the patient speaks to a relevant agency, such as a debt advice charity, who can help address the underlying cause of the crisis and who will also be able to refer to a food bank.
"Over 23,000 professionals nationwide are registered as food bank voucher holders, enabling them to refer to their local Trussell Trust food bank."