A national "commissioning gap" is putting anorexic patients at higher risk, an inquest heard.
Dr Katie Bramall-Stainer, chief executive of Cambridgeshire Local Medical Committee, told an inquest into Averil Hart's death she had "deep concerns" about a lack of formally commissioned medical monitoring.
She said gaps were "potentially harmful and negligent" to these vulnerable patients.
Miss Hart, 19, died in December 2012.
The student from Newton in Suffolk, collapsed while studying at the University of East Anglia (UEA) in Norwich in December, and died from complications from anorexia days later.
She had previously been treated at the eating disorder unit at Addenbrooke's Hospital in Cambridge for 10 months.
Dr Bramall-Stainer said: "The national picture is one of a failure to have a sustainable, safe, evidence-based, adequately commissioned position for patients to ensure long-term positive outcomes".
"Where there's an absence of commissioning around specialist services and monitoring in the community it's the patient that suffers and I fail to understand, as a GP, how a developed nation in 2020 couldn't be putting the requisite focus and resource and governance around this incredibly vulnerable and fragile cohort of patients who can relapse quickly and relapse seriously, with too often tragic outcomes," she said.
Severe and enduring anorexia patients have a mortality rate of 12.5% per annum compared to 2% for suspected cancer referrals, the inquest heard.
Assistant coroner Sean Horstead said he had previously heard evidence of a lack of formal primary care commissioning, including medical monitoring, in multiple areas of the east of England, including Essex, Suffolk, Bedfordshire and Luton and Hertfordshire.
When asked if this was worrying, Dr Bramall-Stainer said this was "a deep concern" especially as high risk anorexia patients often "carry the highest mortality risk".
The inquest heard the lack of formal commissioning for medical monitoring and primary care for eating disorder patients had been a problem since before Miss Hart's death in 2012.
GPs in Cambridgeshire previously rejected a proposal to take on medical monitoring due to concerns including surgery capacity.
A new pilot scheme has been proposed which would involve specially trained health care assistants monitoring low to moderate risk patients.
High risk patients would be monitored by the eating disorder service.
The inquest at Huntingdon continues.
If you are affected by any of the issues in this story, you can talk in confidence to eating disorders charity Beat by calling its adult helpline on 0808 801 0677 or youth helpline on 0808 801 0711.