The editors of a leading journal suggest that the poor diet of shift workers should be considered an occupational health hazard. They argue that working patterns should be treated as a specific risk factor for obesity and type 2 diabetes, which have reached epidemic proportions in the developed world, with the developing world not far behind.

With reference to studies published in earlier issues of the journal, that show links between increased risk in type 2 diabetes and shift work patterns in American nurses, Dr Virginia Barbour, chief editor of the journal PLoS Medicine and her fellow editors make a case in this month's edition for classing unhealthy eating as a new form of occupational hazard, especially in those workplaces that employ shift workers, whose easy access to junk food compared to healthier options just makes it harder to keep to a good diet.

Shift work is common in both the developed and the developing world. About 15 to 20% of workers in Europe and the US work shifts, many of them in the health care industry.

As the world moves more toward the 24/7 pattern of "open all hours", shift work will become even more common than this, and if the data from studies cited in their editorial are to be taken at face value, then this pattern of work has the "potential to accelerate the progression of the global epidemic of obesity and diabetes," write the PLoS editors.

They refer to "compelling evidence" in a paper by An Pan and others published in PLoS Medicine earlier this year that found strong links between rotating night shift work and risk of type 2 diabetes. In that paper, the researchers analyzed 18-20 years of follow up data from the long-running US Nurses Health Study (NHS).

Pan and colleagues noted that there is now good evidence that proper screening and intervention are needed to prevent diabetes in rotating night shift workers.

Although diet is only one of the risk factors for diabetes, it is an obvious target for intervention, being potentially easier to change than others such as the "metabolic consequences of a deranged circadian rhythm", argue the editors.

However, a move in this direction takes occupational health and safety even further away from its once traditional territory of environmental hazards towards something more "personal": the diet of workers. Such a transition requires what the editors describe as a "change in thinking" that is, however, "not unthinkable".

Steps into this personal arena have already been taken, with attempts to "encourage" employers to help their workers eat more healthily. But the editors question the seriousness of those efforts and contrast them with the much more "prescriptive" approach that has been taken with reducing exposure to tobacco smoke.

Workplaces that employ shift workers could lead the way in such a drive, and the editors offer the Cleveland Clinic, where incentives for healthy eating, along with exercise and smoking cessation, have led to measurable improvement in employee health.

The PLoS editors suggest however, that perhaps the time has come to move from simple persuasion, or telling people what they already know about the need for a healthy diet, to concrete action: "governments need to legislate to improve the habits of consumers and take specific steps to ensure that it is easier and cheaper to eat healthily than not," they write.

Way back, when laws that regulate workers' physical safety were introduced, occupational injuries and deaths fell. We are now at a similar threshold, but this time the issue is unhealthy eating, and the effect on public health of bringing in laws to cover it could be even greater, argue the editors.

Written by Catharine Paddock PhD