Writing in the Sun, Kelvin MacKenzie recounts how he took part in a television discussion about the links between obesity and poverty, when a fellow panellist said to him: “It’s all right for you, shopping at Waitrose”.

Mr MacKenzie then defends his choice of supermarket by saying it is the nearest to where he lives and as “any food retailer will tell you – thanks to their extensive research – no customer wants to travel more than one and a quarter miles to shop. It’s why supermarkets build more and more stores”.

If he is correct, then Waitrose must locate its shops where there are fewer obese people – and as it adds more stores then it will have more “problem” shoppers, where I use the term “problem” loosely.

Research by Kantar Worldpanel plots the major supermarkets and independent shops on to a graph showing the percentage of ‘upmarket’ shoppers and the relative number of shoppers with a body mass index of more than 30.

graph showing obesity and class

At the top left of the graph sits Waitrose, with around 73 per cent of shoppers being in the ABC1 social classes (lower to upper middle class) and 35 per cent fewer overweight shoppers than the average grocery shop. Tesco lean slightly towards ABC1s, at 55 per cent and has around 5 per cent more overweight shoppers than the average.

Independent local shops are massively low on ABC1s, with around 37 per cent, and have around 6 per cent fewer overweight shoppers than the average.

Which tells us that the average local shop is likely to be trading with fewer upmarket customers than the supermarkets but its shoppers are less likely to be obese. By extension you could say that local shops serve more poor people, but fewer obese people.

If independents, which only have a 2.1 per cent share of the market as calculated by Kantar, were a multiple, its management would be seeking to increase the number of ABC1s they attracted and to attract them with a healthy range.

The competitor they would be benchmarking themselves against would be the Co-op, which has 47 per cent ABC1 shoppers and 15 per cent fewer overweight shoppers. If you are interested in the Co-op model, it has plenty of new c-stores open around the country – one in every postcode.