An action plan will be drawn up in an effort to better tackle major public-health challenges such as obesity, mental health and inactivity.

The Scottish Government said it would develop a national strategy after a review group found there was a "perceived lack of cohesion" in current efforts.

The expert group, commissioned by the Government and chaired by Dr Hamish Wilson, found "weak" co-ordination between the work being carried out at national, regional and local levels.

More clarity is needed on the roles and responsibilities of different organisations and how they join up, its report concluded.

"The current arrangements, with responsibility for different domains sitting within different organisations, lessens the effectiveness, awareness and understanding of the totality of the public-health effort," it said.

Other recommendations include a greater role for public-health workers within the ongoing integration of health and social care, and a further review of the organisational arrangements in Scotland.

Responding to the report, public health minister Maureen Watt said: "Scotland has a strong reputation in public health and substantial progress has been made in a number of areas.

"However, deep-seated issues, including obesity, mental-health problems and health inequalities, still need to be tackled. As this report recognises, this requires a wide response from across society, beyond the traditional boundaries of the NHS.

"I particularly welcome the call for a single public-health strategy for Scotland. There are many dedicated professionals working to improve public health - in health boards, local councils, charities, communities and academia.

"A national strategy will help to identify shared priorities and bring a new focus to our efforts."