Doctors and nurses must "change how they use their time" so they can take every opportunity to talk to patients about issues such as smoking and obesity, according to a new report.
Government advisers from the NHS Future Forum also said patients expected NHS staff to be healthy themselves and for the health service to "put its own house in order" before dictating to them.
The forum is supporting the Department of Health on steps that need to be taken to realise ambitions behind the Health and Social Care Bill, currently going through Parliament.
It called for NHS staff to "make every contact count" to maintain or improve patients' mental and physical health and wellbeing.
As well as doctors and nurses, this should include pharmacists, midwives, optometrists, dentists, physiotherapists and health visitors.
Health Secretary Andrew Lansley should emphasise the importance of this step by including it in the legally-binding NHS Constitution, the report went on.
It added: "There are millions of opportunities every day for the NHS to help to improve people's health and wellbeing and reduce health inequalities, but to take this opportunity it needs a different view of how to use its contacts with the public.
"A routine dental check-up or eye test, for example, is a chance to offer advice to help someone stop smoking ... A visit from a midwife or health visitor is an opportunity to talk about a new parent's anxieties and consider options for accessing mental health support."
At an individual level, healthcare professionals "must change how they use their time", the report said.
"They must understand that this is a part of their job, and be supported to have the skills and knowledge they need to make every contact count."
Steps should also be taken to improve the health of the 1.4 million people working in the NHS, the experts said.
"A very strong message from our engagement is that, if we expect healthcare professionals to improve the health and wellbeing of the people they meet in the course of their work, the NHS must first 'put its own house in order'."
"We ... heard from patients and the public that it is harder to accept messages from the NHS if it is clear they do not follow these messages for their own health."
The report also called for steps to improve the sharing of data about patients, with their consent, between different organisations.
It also called for people to have greater access to their own medical records - something that has been a long-term ambition for the NHS.
The experts said patient access to records is "still the exception to the rule".
They added: "Though patient demand for access to their health records is currently low, it is growing, in line with wider trends in society."
The team also made recommendations on the greater integration of services, particularly between health and social care.
The forum listened to more than 11,000 people face-to-face at more than 300 events for its report.
The health secretary said it was "essential" that the thoughts of patients and clinicians were listened to and said the NHS Future Forum had provided "invaluable feedback and advice on what the NHS needs to do to improve results and put the NHS truly on the side of patients".
"We are taking forward modernisation within the NHS in partnership with professional leaders from the service. I'm pleased to accept all their recommendations."
NHS Confederation deputy policy director Jo Webber said: "It is right to say that the reforms are going to be a massive leadership challenge and local leaders will need to be supported both in making the changes specified in the reforms and in making them work."
Barbara Young, chief executive of Diabetes UK, said there was "much to welcome" in the report but the charity had concerns about how the reforms would ensure access to uniform care.
"The post-code lottery for people with diabetes is already unacceptable and our great fear is that this could make the disparity in quality of care even worse," she added.