Can the opening of a superstore in a highly deprived part of one of our major cities lead to any significant improvement in the diet of local residents? It sounds like a trite question. But those attending a seminar organised by the British Retail Consortium last week heard there is finally some evidence - independent evidence to boot - to suggest this is exactly what can happen.
The research in question was conducted by academics from the University of Southampton as part of a major project called Food Deserts in British Cities. They examined what happened to food consumption in the Seacroft area of Leeds, where there was very poor retail provision until the opening of a Tesco superstore in the area in November 2000.
At the heart of the research is a comprehensive before and after' study ­ based on food consumption diaries filled in by residents ­ which suggests that improved retail access in the area was accompanied by a statistically significant improvement in the consumption of fruit and veg among some groups of residents.
Now, that good news needs to be put into some sort of context, admits Professor Neil Wrigley, one of the report's authors.
"Those changes in diet were small in absolute terms ­ an increase in the order of approximately three portions per week," he says, "Set against the current guidance of at least five portions a day, the consumption levels of the majority of residents in this deprived area remained significantly at a variance from recommended levels."
Nevertheless, diets did improve. And there is another upside identified by the report ­ the average distance travelled by residents to get to their main food store fell from 2.25km to less than 1km. In addition, walking as a means of getting to that store tripled to more than 30%.
But Wrigley says that poor access to decent food stores is not the sole reason why people have poor diets.
"Food retail access appears to be merely one part of a complex combination of critical barriers which must be overcome if fruit and vegetable consumption ­ and by extension diet-related health ­ is to be improved in deprived areas of British cities."
The BRC's director general Bill Moyes agrees there are no quick wins to tackling the issues that stand in the way of improving diet. But the reason the BRC is so excited about the University of Southampton research is that for the first time there is evidence that opening big stores as part of the process of regenerating deprived areas, such as Seacroft, can offer part of the solution for tackling food poverty problems.
This is significant for a number of reasons, not least the fact that the BRC feels there is still an "emotional bias" against large retailers when it comes to regeneration schemes.
There's no denying that the whole issue of so called food deserts has become highly emotive ­ and political. When policy makers first began discussing the complex issues surrounding social exclusion, health inequalities and food poverty in the late 1990s, they seized upon food deserts as a handy metaphor for the problems faced by those living in areas of urban deprivation. In addition, policymakers seemed to favour the notion that small scale, local retail solutions were the best way of improving the diet of those living in such communities.
However, it soon became clear there was a lack of real scientific evidence to support policy developments. Well, that evidence is now starting to appear.
The Food Deserts in British Cities project will be joined early next year by a separate study from the University of Newcastle, funded by the Food Standards Agency.
And there is a further study under way at the Universities of Glasgow and Stirling.
As far as the big food chains are concerned, the results already coming through support their view that supermarkets have not caused food deserts. And if these deserts do exist, so they argue, then supermarkets are unlikely to be the problem but are instead part of the solution.
As the BRC's Moyes said at last week's seminar: "This significant piece of research should be taken seriously by the government in its approach to planning, regeneration and improved diet.
"It underlines the fact that if retail-led regeneration in deprived areas is to be effective, policymakers must not allow emotional bias against large retailers to skew their judgement of what works."