Of course, we want something more than success measured by the tightly defined academic outcomes revealed by NAPLAN.

How can we accept a situation where children leave primary school knowing more about punctuation and multiplication than they do about their bodies, how they work and what keeps them alive?

Schools are a great place to do things that benefit children, young people and society as a whole. Inevitably, schools are called upon to better prepare their students to cope with a wide range of issues we confront as a community.

This is certainly true of health education, which is more relevant than ever given the prevalence of chronic disease and paramount importance of an effective national preventive health strategy.

Schools have a critical role to play in equipping young Australians with the knowledge, skills and attitudes needed to make positive decisions about their health.

We need to make sure our kids leave primary school fully appreciating how amazing their bodies are, what they are capable of and the importance of caring for them thoughtfully. Fortunately, leading public health figures who have captured the attention of policy makers in Canberra recognise this. But what they fail to appreciate is the limited capacity of primary schools to play the role they expect of them.

It is convenient to simply assume that, as health education forms part of the primary-school curriculum, it just happens. Unfortunately, it's not that straightforward.

The reality is most primary schools struggle to effectively deliver the existing health curriculum, let alone a new, national curriculum that is likely to place more onerous claims on them.

These constraints are well understood among stakeholders familiar with the operating environment in primary schools.

A recent report produced by the NSW Auditor-General provides useful insight. It documents the issues that limit the quantity and quality of teaching time devoted to a key learning area - in this instance, physical education.

The report isn't critical of primary school teachers. It simply acknowledges the reality of the situation in classrooms across Australia.

The limiting factor is the capacity of the school - a function of fixed school hours, the breadth of the curriculum as well as the skills and experience of teachers to teach all aspects of it effectively.

This isn't a recent development. Teachers have been operating under escalating pressures for many years. Primary school teachers are trained as generalists and are expected to teach across all subject areas.

Although English and maths command more than half of teaching time, the disproportionate focus on literacy and numeracy standards exerts pressure on schools to allocate even more time to the core.

Interest groups associated with other key learning areas advocate for larger allocations of teaching time: the post-Olympics call for more school sport is but the most recent example.

At the same time teachers need to deal with students with special needs, class management issues, parental concerns, more assessments and constantly evolving reporting methods.

The traditional response, by education departments and many others, is to offer teachers professional development opportunities as well as resources to support delivery of those parts of the curriculum that aren't receiving the attention we would prefer.

While enabling the department to ''tick the box'', this classic top-down response doesn't address the root cause of the problem.

Teachers still have to make priorities. Given the limited opportunities for professional development, and the pressures mounting on other fronts, teachers are hardly going to choose to increase their skills in a deprioritised subject area.

Even if they do receive some form of one-off professional development, nothing changes.

Primary school teachers can't be expected to do everything as well as we expect them to.

More realistic responses involve partnerships with qualified third parties that add to the school's capacity to meet community expectations.

Life Education is a partner for many Australian primary schools, delivering health education, tackling - where appropriate - issues about drugs such as medicines, tobacco and alcohol.

Last year we worked in 3550 preschools and schools, making our program available to the 621,000 students in their care.

Effective health education, particularly drug education, is challenging and can be controversial. The objective is for students to learn in a way that genuinely informs their attitudes, values and beliefs and helps them to develop skills that allow them to make informed choices.

It is work that is greatly enhanced by highly trained educators with specific skills in delivering health education. If we are serious about building the capacity of primary schools to positively influence the future of pupils, it is a sensible model for schools and school systems to follow.

David Ballhausen is the chief executive of Life Education Australia, an NGO providing drug and health education in schools.