Time to say goodbye to the haggis, black pudding and rarebit. If the Scots, Irish and Welsh ate like the English it would save 4,000 lives a year.

Researchers made the calculation after studying the average diets in each country and the death rates from cancer, heart disease and stroke. They call for a fat tax, combined with subsidies for fruit and vegetables, to change eating habits and reduce deaths in the UK.

Peter Scarborough, of the department for public health at the University of Oxford, who led the study published in the journal BMJ Open, said: "The chief dietary factor that is driving this mortality gap is fruit and vegetables. Consumption of fruit and vegetables in Scotland is around 12 per cent lower than in England, and about 20 per cent lower in Northern Ireland.

"We believe that taxes on salt and saturated fat, coupled with subsidies for fruit and vegetables, should be considered," Dr Scarborough said.