People with severe mental illness are still receiving worryingly sub-standard levels of physical care, a report says.
Mental illness is often associated with physical problems
Experts believe poor physical care contributes towards a three times higher rate of premature death among those with severe mental problems.
This group is at greater risk of physical illness, often due to their mental illness and lifestyle factors.
Among those contributing to the report are mental health charities Rethink and Sane, and the Royal College of Nursing.
The report calls for a holistic approach to treating mental health, with physical and lifestyle factors playing an important role.
Figures show that people with severe mental illness have up to five times the risk of the general population of diabetes, and twice the risk of cardiovascular disease and respiratory diseases.
Government guidance recommends that people being treated for severe mental health problems should undergo assessments of their physical health.
But the latest study found 89% claimed not to have had a record of their health history taken, and seven out of 10 said they had not been offered lifestyle management advice.
Paul Corry of the charity Rethink said: "The report reveals that those affected by serious mental illness are being neglected and offered an unacceptable level of care, despite being more at risk of some of the most common physical illnesses than the general population."
Marjorie Wallace, chief executive of Sane, said adopting a holistic approach would help to improve the overall health and daily lives of many people.
The National institute for Mental Health in England said work was under way to spread good practice across Britain.
"We look forward to working closely with those involved in developing this report to address this serious issue."
Severe mental illnesses is usually defined as schizophrenia and bipolar disorder (manic depression).
Sue Carroll has benefited from the holistic approach on offer at the Brixton Wellbeing Support Programme in south London.
Sue has struggled with a range of severe mental illness since a breakdown in 1982 forced her to give up her work as a nurse.
She underwent drug and ECT therapy and was sectioned four times.
Two years ago, she was referred to the Brixton project and now attends three times a week, regularly joining trips to the local lido and gym.
"It gets me out of the house and helps me to meet new people," she said.
"Before I was quite isolated, and had very low self-esteem.
"The project has had a tremendous impact on my life."