A year after responsibility for public health was transferred from the NHS to local authorities, the BMJ found numerous examples of councils disinvesting in a wide range of public health services, including those for substance misuse, sexual health, smoking cessation, obesity, and school nursing.
Much of this money is being used to support wider council services vulnerable to cuts, such as trading standards, domestic abuse services, housing, parks and leisure centres.
The BMJ sent Freedom of Information requests to all 152 upper-tier local authorities in England, asking how they have been spending the money that was transferred to them for public health from April 2013, and how they intend to spend it in the coming year.
Of the 143 (94%) of councils that responded, almost a third (45) said they have de-commissioned at least one service since April 2013, while others have reduced funding to certain services. The majority also indicated that more ambitious service changes would occur in 2014/15.
It provides clear evidence that local authorities up and down the country are dipping into the public health budget to prop up other services.
For example, Sheffield said it had "top sliced" 11% of contract values on almost all of the services commissioned from the public health grant last year, freeing up funds to pay for activities previously paid for by mainstream council funds.
In Derbyshire, there are plans to reduce investment in substance misuse, sexual health, smoking, and obesity services and re-invest £2m "to support wider preventative programmes that are under review due to council financial pressures."
Gateshead has consulted on a proposal to reduce funding for the provision of drug and alcohol treatment by 30%.
Meanwhile, Nottingham City plans to "adjust spending of £5.8m in line with the Council priorities" through a combination of "service re-design, integration of smaller contracts into larger contracts and some de-commissioning."
One leading clinician described the redeployment of funds as "robbing Peter to pay Paul," and said local authorities are "playing fast and loose with public health budgets." Some doctors are concerned that such widespread plundering will damage public health overall.
The BMJ also found that public health staff in parts of the country are being scaled back to save money. For example, Sandwell Council in the West Midlands told the BMJ it had saved £2m through loss of staff under a mutually agreed resignation scheme since April 2013.
A recent survey of public health professionals by the British Medical Association (BMA) also revealed fears about future staffing levels in public health, with just 12% believing there would be sufficient consultant posts available to serve the needs of the population in ten years time.
And the Association of Directors of Public Health (ADPH) told the BMJ it was concerned about a vacuum in public health leadership at the top of local government, with a quarter of Director posts currently temporary or unfilled.
Despite the concerns, Public Health England said it was right for public health grants - totalling £2.8bn across England for 2014/15 - to be used to leverage wider public health benefit across the far larger spend of local government.
Its Chief Executive, Duncan Selbie, said he welcomed local government reviewing where the money has been spent, saying "the duty is to improve the public's health, not to provide a public health service." And he insisted that public health professionals "have more influence now" in local government than they did when working within the NHS.